diff --git a/quantum/api.h b/quantum/api.h
index 90a4de83393..0a30e9d6cc8 100644
--- a/quantum/api.h
+++ b/quantum/api.h
@@ -14,8 +14,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef _API_H_
-#define _API_H_
+#pragma once
 
 #ifdef __AVR__
 #    include "lufa.h"
@@ -54,5 +53,3 @@ __attribute__((weak)) bool process_api_quantum(uint8_t length, uint8_t* data);
 __attribute__((weak)) bool process_api_keyboard(uint8_t length, uint8_t* data);
 
 __attribute__((weak)) bool process_api_user(uint8_t length, uint8_t* data);
-
-#endif
diff --git a/quantum/api/api_sysex.h b/quantum/api/api_sysex.h
index 58b8cbb663c..382f4bea440 100644
--- a/quantum/api/api_sysex.h
+++ b/quantum/api/api_sysex.h
@@ -14,13 +14,10 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef _API_SYSEX_H_
-#define _API_SYSEX_H_
+#pragma once
 
 #include "api.h"
 
 void send_bytes_sysex(uint8_t message_type, uint8_t data_type, uint8_t* bytes, uint16_t length);
 
 #define SEND_BYTES(mt, dt, b, l) send_bytes_sysex(mt, dt, b, l)
-
-#endif
diff --git a/quantum/audio/audio.h b/quantum/audio/audio.h
index 805cb4f7ab7..bc00cd19e6a 100644
--- a/quantum/audio/audio.h
+++ b/quantum/audio/audio.h
@@ -13,8 +13,8 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
-#ifndef AUDIO_H
-#define AUDIO_H
+
+#pragma once
 
 #include <stdint.h>
 #include <stdbool.h>
@@ -103,5 +103,3 @@ void play_notes(float (*np)[][2], uint16_t n_count, bool n_repeat);
 #define PLAY_LOOP(note_array) play_notes(&note_array, NOTE_ARRAY_SIZE((note_array)), true)
 
 bool is_playing_notes(void);
-
-#endif
diff --git a/quantum/audio/luts.h b/quantum/audio/luts.h
index 6fdd3b4635d..74980b292ed 100644
--- a/quantum/audio/luts.h
+++ b/quantum/audio/luts.h
@@ -14,6 +14,8 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#pragma once
+
 #if defined(__AVR__)
 #    include <avr/io.h>
 #    include <avr/interrupt.h>
@@ -23,14 +25,9 @@
 #    include <hal.h>
 #endif
 
-#ifndef LUTS_H
-#    define LUTS_H
-
-#    define VIBRATO_LUT_LENGTH 20
+#define VIBRATO_LUT_LENGTH 20
 
-#    define FREQUENCY_LUT_LENGTH 349
+#define FREQUENCY_LUT_LENGTH 349
 
 extern const float    vibrato_lut[VIBRATO_LUT_LENGTH];
 extern const uint16_t frequency_lut[FREQUENCY_LUT_LENGTH];
-
-#endif /* LUTS_H */
diff --git a/quantum/audio/muse.h b/quantum/audio/muse.h
index 6f382a7fee0..ad2f96e43af 100644
--- a/quantum/audio/muse.h
+++ b/quantum/audio/muse.h
@@ -1,9 +1,6 @@
-#ifndef MUSE_H
-#define MUSE_H
+#pragma once
 
 #include "quantum.h"
 #include "process_audio.h"
 
 uint8_t muse_clock_pulse(void);
-
-#endif
diff --git a/quantum/audio/musical_notes.h b/quantum/audio/musical_notes.h
index 9742e19c434..8ac6aafd38f 100644
--- a/quantum/audio/musical_notes.h
+++ b/quantum/audio/musical_notes.h
@@ -14,8 +14,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef MUSICAL_NOTES_H
-#define MUSICAL_NOTES_H
+#pragma once
 
 // Tempo Placeholder
 #define TEMPO_DEFAULT 100
@@ -229,5 +228,3 @@
 #define NOTE_GF8 NOTE_FS8
 #define NOTE_AF8 NOTE_GS8
 #define NOTE_BF8 NOTE_AS8
-
-#endif
diff --git a/quantum/audio/voices.h b/quantum/audio/voices.h
index 0c45b0720e8..abafa2b404e 100644
--- a/quantum/audio/voices.h
+++ b/quantum/audio/voices.h
@@ -13,6 +13,9 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
+
+#pragma once
+
 #include <stdint.h>
 #include <stdbool.h>
 #if defined(__AVR__)
@@ -21,14 +24,11 @@
 #include "wait.h"
 #include "luts.h"
 
-#ifndef VOICES_H
-#    define VOICES_H
-
 float voice_envelope(float frequency);
 
 typedef enum {
     default_voice,
-#    ifdef AUDIO_VOICES
+#ifdef AUDIO_VOICES
     something,
     drums,
     butts_fader,
@@ -41,12 +41,10 @@ typedef enum {
 // duty_fourth_down,
 // duty_third_down,
 // duty_fifth_third_down,
-#    endif
+#endif
     number_of_voices  // important that this is last
 } voice_type;
 
 void set_voice(voice_type v);
 void voice_iterate(void);
 void voice_deiterate(void);
-
-#endif
diff --git a/quantum/color.h b/quantum/color.h
index f0ee7827572..7448168b3ad 100644
--- a/quantum/color.h
+++ b/quantum/color.h
@@ -14,8 +14,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef COLOR_H
-#define COLOR_H
+#pragma once
 
 #include <stdint.h>
 #include <stdbool.h>
@@ -86,4 +85,3 @@ RGB hsv_to_rgb_nocie(HSV hsv);
 #ifdef RGBW
 void convert_rgb_to_rgbw(LED_TYPE *led);
 #endif
-#endif  // COLOR_H
diff --git a/quantum/keycode_config.h b/quantum/keycode_config.h
index aa75ba2c132..f878168c5fb 100644
--- a/quantum/keycode_config.h
+++ b/quantum/keycode_config.h
@@ -14,13 +14,12 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#pragma once
+
 #include "eeconfig.h"
 #include "keycode.h"
 #include "action_code.h"
 
-#ifndef KEYCODE_CONFIG_H
-#    define KEYCODE_CONFIG_H
-
 uint16_t keycode_config(uint16_t keycode);
 uint8_t  mod_config(uint8_t mod);
 
@@ -42,5 +41,3 @@ typedef union {
 } keymap_config_t;
 
 extern keymap_config_t keymap_config;
-
-#endif /* KEYCODE_CONFIG_H */
diff --git a/quantum/keymap.h b/quantum/keymap.h
index 90a2398ba4a..191e8139778 100644
--- a/quantum/keymap.h
+++ b/quantum/keymap.h
@@ -15,8 +15,7 @@ You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#ifndef KEYMAP_H
-#define KEYMAP_H
+#pragma once
 
 #include <stdint.h>
 #include <stdbool.h>
@@ -55,5 +54,3 @@ uint16_t keymap_function_id_to_action(uint16_t function_id);
 
 extern const uint16_t keymaps[][MATRIX_ROWS][MATRIX_COLS];
 extern const uint16_t fn_actions[];
-
-#endif
diff --git a/quantum/keymap_extras/keymap_nordic.h b/quantum/keymap_extras/keymap_nordic.h
index 8d2f76f2732..76d2f4f6b0b 100644
--- a/quantum/keymap_extras/keymap_nordic.h
+++ b/quantum/keymap_extras/keymap_nordic.h
@@ -13,8 +13,8 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
-#ifndef KEYMAP_NORDIC_H
-#define KEYMAP_NORDIC_H
+
+#pragma once
 
 #include "keymap.h"
 
@@ -66,5 +66,3 @@
 
 #define NO_BSLS ALGR(KC_MINS)
 #define NO_MU ALGR(KC_M)
-
-#endif
diff --git a/quantum/keymap_extras/keymap_plover_dvorak.h b/quantum/keymap_extras/keymap_plover_dvorak.h
index d40ff5c6bb5..445a1231511 100644
--- a/quantum/keymap_extras/keymap_plover_dvorak.h
+++ b/quantum/keymap_extras/keymap_plover_dvorak.h
@@ -13,8 +13,8 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
-#ifndef KEYMAP_PLOVER_DVORAK_H
-#define KEYMAP_PLOVER_DVORAK_H
+
+#pragma once
 
 #include "keymap_dvorak.h"
 
@@ -43,5 +43,3 @@
 #define PD_O DV_V
 #define PD_E DV_N
 #define PD_U DV_M
-
-#endif
diff --git a/quantum/keymap_extras/keymap_steno.h b/quantum/keymap_extras/keymap_steno.h
index 31dcbf70649..b9115fb8bf9 100644
--- a/quantum/keymap_extras/keymap_steno.h
+++ b/quantum/keymap_extras/keymap_steno.h
@@ -13,8 +13,8 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
-#ifndef KEYMAP_STENO_H
-#define KEYMAP_STENO_H
+
+#pragma once
 
 #include "keymap.h"
 
@@ -72,5 +72,3 @@ enum steno_keycodes {
     STN_ZR,
     STN__MAX = STN_ZR,  // must be less than QK_STENO_BOLT
 };
-
-#endif
diff --git a/quantum/led_matrix.h b/quantum/led_matrix.h
index 5867ba98765..7dcdf1d4823 100644
--- a/quantum/led_matrix.h
+++ b/quantum/led_matrix.h
@@ -17,8 +17,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef LED_MATRIX_H
-#define LED_MATRIX_H
+#pragma once
 
 #ifndef BACKLIGHT_ENABLE
 #    error You must define BACKLIGHT_ENABLE with LED_MATRIX_ENABLE
@@ -123,5 +122,3 @@ typedef struct {
 } led_matrix_driver_t;
 
 extern const led_matrix_driver_t led_matrix_driver;
-
-#endif
diff --git a/quantum/led_tables.h b/quantum/led_tables.h
index 8052d566cf9..cd3e5d74c11 100644
--- a/quantum/led_tables.h
+++ b/quantum/led_tables.h
@@ -13,8 +13,7 @@ You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#ifndef LED_TABLES_H
-#define LED_TABLES_H
+#pragma once
 
 #include "progmem.h"
 #include <stdint.h>
@@ -22,5 +21,3 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #ifdef USE_CIE1931_CURVE
 extern const uint8_t CIE1931_CURVE[] PROGMEM;
 #endif
-
-#endif
diff --git a/quantum/pointing_device.h b/quantum/pointing_device.h
index 29398ebb3ac..aa074bb37d7 100644
--- a/quantum/pointing_device.h
+++ b/quantum/pointing_device.h
@@ -15,8 +15,7 @@ You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#ifndef POINTING_DEVICE_H
-#define POINTING_DEVICE_H
+#pragma once
 
 #include <stdint.h>
 #include "host.h"
@@ -27,5 +26,3 @@ void           pointing_device_task(void);
 void           pointing_device_send(void);
 report_mouse_t pointing_device_get_report(void);
 void           pointing_device_set_report(report_mouse_t newMouseReport);
-
-#endif
diff --git a/quantum/process_keycode/process_audio.h b/quantum/process_keycode/process_audio.h
index 3a84c3d8691..d89a834ea85 100644
--- a/quantum/process_keycode/process_audio.h
+++ b/quantum/process_keycode/process_audio.h
@@ -1,5 +1,4 @@
-#ifndef PROCESS_AUDIO_H
-#define PROCESS_AUDIO_H
+#pragma once
 
 float compute_freq_for_midi_note(uint8_t note);
 
@@ -9,5 +8,3 @@ void process_audio_noteoff(uint8_t note);
 void process_audio_all_notes_off(void);
 
 void audio_on_user(void);
-
-#endif
diff --git a/quantum/process_keycode/process_clicky.h b/quantum/process_keycode/process_clicky.h
index f746edb9519..67b6463c5d4 100644
--- a/quantum/process_keycode/process_clicky.h
+++ b/quantum/process_keycode/process_clicky.h
@@ -1,5 +1,4 @@
-#ifndef PROCESS_CLICKY_H
-#define PROCESS_CLICKY_H
+#pragma once
 
 void clicky_play(void);
 bool process_clicky(uint16_t keycode, keyrecord_t *record);
@@ -13,5 +12,3 @@ void clicky_on(void);
 void clicky_off(void);
 
 bool is_clicky_on(void);
-
-#endif
diff --git a/quantum/process_keycode/process_combo.h b/quantum/process_keycode/process_combo.h
index 0f01aae93ed..e51a2f1f4e2 100644
--- a/quantum/process_keycode/process_combo.h
+++ b/quantum/process_keycode/process_combo.h
@@ -14,8 +14,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef PROCESS_COMBO_H
-#define PROCESS_COMBO_H
+#pragma once
 
 #include "progmem.h"
 #include "quantum.h"
@@ -62,5 +61,3 @@ void combo_enable(void);
 void combo_disable(void);
 void combo_toggle(void);
 bool is_combo_enabled(void);
-
-#endif
diff --git a/quantum/process_keycode/process_key_lock.h b/quantum/process_keycode/process_key_lock.h
index a8e110a4bf9..baa0b39077a 100644
--- a/quantum/process_keycode/process_key_lock.h
+++ b/quantum/process_keycode/process_key_lock.h
@@ -14,11 +14,8 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef PROCESS_KEY_LOCK_H
-#define PROCESS_KEY_LOCK_H
+#pragma once
 
 #include "quantum.h"
 
 bool process_key_lock(uint16_t *keycode, keyrecord_t *record);
-
-#endif  // PROCESS_KEY_LOCK_H
diff --git a/quantum/process_keycode/process_leader.h b/quantum/process_keycode/process_leader.h
index e0edf57b327..9844f27a1bb 100644
--- a/quantum/process_keycode/process_leader.h
+++ b/quantum/process_keycode/process_leader.h
@@ -14,8 +14,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef PROCESS_LEADER_H
-#define PROCESS_LEADER_H
+#pragma once
 
 #include "quantum.h"
 
@@ -37,5 +36,3 @@ void qk_leader_start(void);
     extern uint16_t leader_sequence[5]; \
     extern uint8_t  leader_sequence_size
 #define LEADER_DICTIONARY() if (leading && timer_elapsed(leader_time) > LEADER_TIMEOUT)
-
-#endif
diff --git a/quantum/process_keycode/process_midi.h b/quantum/process_keycode/process_midi.h
index ef5661dd4d1..68c6eda6665 100644
--- a/quantum/process_keycode/process_midi.h
+++ b/quantum/process_keycode/process_midi.h
@@ -14,8 +14,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef PROCESS_MIDI_H
-#define PROCESS_MIDI_H
+#pragma once
 
 #include "quantum.h"
 
@@ -53,5 +52,3 @@ uint8_t midi_compute_note(uint16_t keycode);
 #    endif  // MIDI_ADVANCED
 
 #endif  // MIDI_ENABLE
-
-#endif
diff --git a/quantum/process_keycode/process_music.h b/quantum/process_keycode/process_music.h
index 292bc537424..01014aa6c21 100644
--- a/quantum/process_keycode/process_music.h
+++ b/quantum/process_keycode/process_music.h
@@ -14,8 +14,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef PROCESS_MUSIC_H
-#define PROCESS_MUSIC_H
+#pragma once
 
 #include "quantum.h"
 
@@ -57,5 +56,3 @@ bool music_mask_user(uint16_t keycode);
 #    endif
 
 #endif  // defined(AUDIO_ENABLE) || (defined(MIDI_ENABLE) && defined(MIDI_BASIC))
-
-#endif
diff --git a/quantum/process_keycode/process_printer.h b/quantum/process_keycode/process_printer.h
index 71d3a4b56a6..3c6d06ff94a 100644
--- a/quantum/process_keycode/process_printer.h
+++ b/quantum/process_keycode/process_printer.h
@@ -14,13 +14,10 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef PROCESS_PRINTER_H
-#define PROCESS_PRINTER_H
+#pragma once
 
 #include "quantum.h"
 
 #include "protocol/serial.h"
 
 bool process_printer(uint16_t keycode, keyrecord_t *record);
-
-#endif
diff --git a/quantum/process_keycode/process_steno.h b/quantum/process_keycode/process_steno.h
index ed049eb13fe..d11fd40af06 100644
--- a/quantum/process_keycode/process_steno.h
+++ b/quantum/process_keycode/process_steno.h
@@ -13,8 +13,8 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
-#ifndef PROCESS_STENO_H
-#define PROCESS_STENO_H
+
+#pragma once
 
 #include "quantum.h"
 
@@ -25,5 +25,3 @@ void     steno_init(void);
 void     steno_set_mode(steno_mode_t mode);
 uint8_t *steno_get_state(void);
 uint8_t *steno_get_chord(void);
-
-#endif
diff --git a/quantum/process_keycode/process_tap_dance.h b/quantum/process_keycode/process_tap_dance.h
index 09ceef74d86..a013c5cabf5 100644
--- a/quantum/process_keycode/process_tap_dance.h
+++ b/quantum/process_keycode/process_tap_dance.h
@@ -13,8 +13,8 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
-#ifndef PROCESS_TAP_DANCE_H
-#define PROCESS_TAP_DANCE_H
+
+#pragma once
 
 #ifdef TAP_DANCE_ENABLE
 
@@ -101,5 +101,3 @@ void qk_tap_dance_dual_role_reset(qk_tap_dance_state_t *state, void *user_data);
 #    define TD(n) KC_NO
 
 #endif
-
-#endif
diff --git a/quantum/process_keycode/process_terminal.h b/quantum/process_keycode/process_terminal.h
index 8426f442b66..0159131e5b9 100644
--- a/quantum/process_keycode/process_terminal.h
+++ b/quantum/process_keycode/process_terminal.h
@@ -14,8 +14,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef PROCESS_TERMINAL_H
-#define PROCESS_TERMINAL_H
+#pragma once
 
 #include "quantum.h"
 
@@ -23,5 +22,3 @@ extern const char keycode_to_ascii_lut[58];
 extern const char shifted_keycode_to_ascii_lut[58];
 extern const char terminal_prompt[8];
 bool              process_terminal(uint16_t keycode, keyrecord_t *record);
-
-#endif
\ No newline at end of file
diff --git a/quantum/process_keycode/process_terminal_nop.h b/quantum/process_keycode/process_terminal_nop.h
index 56895b33c30..36e25320c5a 100644
--- a/quantum/process_keycode/process_terminal_nop.h
+++ b/quantum/process_keycode/process_terminal_nop.h
@@ -14,12 +14,9 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef PROCESS_TERMINAL_H
-#define PROCESS_TERMINAL_H
+#pragma once
 
 #include "quantum.h"
 
 #define TERM_ON KC_NO
 #define TERM_OFF KC_NO
-
-#endif
\ No newline at end of file
diff --git a/quantum/quantum_keycodes.h b/quantum/quantum_keycodes.h
index a2cc7b38d91..0160c5586d3 100644
--- a/quantum/quantum_keycodes.h
+++ b/quantum/quantum_keycodes.h
@@ -13,8 +13,8 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
-#ifndef QUANTUM_KEYCODES_H
-#define QUANTUM_KEYCODES_H
+
+#pragma once
 
 #if defined(SEQUENCER_ENABLE)
 #    include "sequencer.h"
@@ -889,5 +889,3 @@ enum quantum_keycodes {
 #define DM_RSTP DYN_REC_STOP
 #define DM_PLY1 DYN_MACRO_PLAY1
 #define DM_PLY2 DYN_MACRO_PLAY2
-
-#endif  // QUANTUM_KEYCODES_H
diff --git a/quantum/rgb.h b/quantum/rgb.h
index 7b6ea0542f2..2602fc0b200 100644
--- a/quantum/rgb.h
+++ b/quantum/rgb.h
@@ -14,8 +14,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef RGB_H
-#define RGB_H
+#pragma once
 
 __attribute__((weak)) void rgblight_toggle(void){};
 
@@ -38,5 +37,3 @@ __attribute__((weak)) void rgblight_decrease_val(void){};
 __attribute__((weak)) void rgblight_increase_speed(void){};
 
 __attribute__((weak)) void rgblight_decrease_speed(void){};
-
-#endif
\ No newline at end of file
diff --git a/quantum/rgb_matrix.h b/quantum/rgb_matrix.h
index 1fd016d79a5..8c80c1bff0c 100644
--- a/quantum/rgb_matrix.h
+++ b/quantum/rgb_matrix.h
@@ -16,8 +16,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef RGB_MATRIX_H
-#define RGB_MATRIX_H
+#pragma once
 
 #include <stdint.h>
 #include <stdbool.h>
@@ -226,5 +225,3 @@ extern last_hit_t g_last_hit_tracker;
 #ifdef RGB_MATRIX_FRAMEBUFFER_EFFECTS
 extern uint8_t g_rgb_frame_buffer[MATRIX_ROWS][MATRIX_COLS];
 #endif
-
-#endif
diff --git a/quantum/rgblight.h b/quantum/rgblight.h
index c3a9e94b7c2..c02fd4f37b6 100644
--- a/quantum/rgblight.h
+++ b/quantum/rgblight.h
@@ -13,8 +13,8 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
-#ifndef RGBLIGHT_H
-#define RGBLIGHT_H
+
+#pragma once
 
 /***** rgblight_mode(mode)/rgblight_mode_noeeprom(mode) ****
 
@@ -437,4 +437,3 @@ void rgblight_effect_twinkle(animation_status_t *anim);
 #    endif
 
 #endif  // #ifndef RGBLIGHT_H_DUMMY_DEFINE
-#endif  // RGBLIGHT_H
diff --git a/quantum/serial_link/protocol/byte_stuffer.h b/quantum/serial_link/protocol/byte_stuffer.h
index 97e8968564a..397ed3baae1 100644
--- a/quantum/serial_link/protocol/byte_stuffer.h
+++ b/quantum/serial_link/protocol/byte_stuffer.h
@@ -22,8 +22,7 @@ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE.
 */
 
-#ifndef SERIAL_LINK_BYTE_STUFFER_H
-#define SERIAL_LINK_BYTE_STUFFER_H
+#pragma once
 
 #include <stdint.h>
 
@@ -33,5 +32,3 @@ SOFTWARE.
 void init_byte_stuffer(void);
 void byte_stuffer_recv_byte(uint8_t link, uint8_t data);
 void byte_stuffer_send_frame(uint8_t link, uint8_t* data, uint16_t size);
-
-#endif
diff --git a/quantum/serial_link/protocol/frame_router.h b/quantum/serial_link/protocol/frame_router.h
index 712250ff359..9325fe4eed9 100644
--- a/quantum/serial_link/protocol/frame_router.h
+++ b/quantum/serial_link/protocol/frame_router.h
@@ -22,8 +22,7 @@ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE.
 */
 
-#ifndef SERIAL_LINK_FRAME_ROUTER_H
-#define SERIAL_LINK_FRAME_ROUTER_H
+#pragma once
 
 #include <stdint.h>
 #include <stdbool.h>
@@ -34,5 +33,3 @@ SOFTWARE.
 void router_set_master(bool master);
 void route_incoming_frame(uint8_t link, uint8_t* data, uint16_t size);
 void router_send_frame(uint8_t destination, uint8_t* data, uint16_t size);
-
-#endif
diff --git a/quantum/serial_link/protocol/frame_validator.h b/quantum/serial_link/protocol/frame_validator.h
index 4a910d510b9..0f78768a00f 100644
--- a/quantum/serial_link/protocol/frame_validator.h
+++ b/quantum/serial_link/protocol/frame_validator.h
@@ -22,13 +22,10 @@ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE.
 */
 
-#ifndef SERIAL_LINK_FRAME_VALIDATOR_H
-#define SERIAL_LINK_FRAME_VALIDATOR_H
+#pragma once
 
 #include <stdint.h>
 
 void validator_recv_frame(uint8_t link, uint8_t* data, uint16_t size);
 // The buffer pointed to by the data needs 4 additional bytes
 void validator_send_frame(uint8_t link, uint8_t* data, uint16_t size);
-
-#endif
diff --git a/quantum/serial_link/protocol/physical.h b/quantum/serial_link/protocol/physical.h
index 425e06cdd29..399c9d1f764 100644
--- a/quantum/serial_link/protocol/physical.h
+++ b/quantum/serial_link/protocol/physical.h
@@ -22,9 +22,6 @@ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE.
 */
 
-#ifndef SERIAL_LINK_PHYSICAL_H
-#define SERIAL_LINK_PHYSICAL_H
+#pragma once
 
 void send_data(uint8_t link, const uint8_t* data, uint16_t size);
-
-#endif
diff --git a/quantum/serial_link/protocol/transport.h b/quantum/serial_link/protocol/transport.h
index 309a56b000a..3ce0c9fe4e6 100644
--- a/quantum/serial_link/protocol/transport.h
+++ b/quantum/serial_link/protocol/transport.h
@@ -22,8 +22,7 @@ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE.
 */
 
-#ifndef SERIAL_LINK_TRANSPORT_H
-#define SERIAL_LINK_TRANSPORT_H
+#pragma once
 
 #include "serial_link/protocol/triple_buffered_object.h"
 #include "serial_link/system/serial_link.h"
@@ -138,5 +137,3 @@ void add_remote_objects(remote_object_t** remote_objects, uint32_t num_remote_ob
 void reinitialize_serial_link_transport(void);
 void transport_recv_frame(uint8_t from, uint8_t* data, uint16_t size);
 void update_transport(void);
-
-#endif
diff --git a/quantum/serial_link/protocol/triple_buffered_object.h b/quantum/serial_link/protocol/triple_buffered_object.h
index 6ec98d52bf4..717d6d7b8be 100644
--- a/quantum/serial_link/protocol/triple_buffered_object.h
+++ b/quantum/serial_link/protocol/triple_buffered_object.h
@@ -22,8 +22,7 @@ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE.
 */
 
-#ifndef SERIAL_LINK_TRIPLE_BUFFERED_OBJECT_H
-#define SERIAL_LINK_TRIPLE_BUFFERED_OBJECT_H
+#pragma once
 
 #include <stdint.h>
 
@@ -43,5 +42,3 @@ void triple_buffer_init(triple_buffer_object_t* object);
 void* triple_buffer_begin_write_internal(uint16_t object_size, triple_buffer_object_t* object);
 void  triple_buffer_end_write_internal(triple_buffer_object_t* object);
 void* triple_buffer_read_internal(uint16_t object_size, triple_buffer_object_t* object);
-
-#endif
diff --git a/quantum/serial_link/system/serial_link.h b/quantum/serial_link/system/serial_link.h
index b6a47395751..adc1f6e93d0 100644
--- a/quantum/serial_link/system/serial_link.h
+++ b/quantum/serial_link/system/serial_link.h
@@ -22,8 +22,7 @@ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE.
 */
 
-#ifndef SERIAL_LINK_H
-#define SERIAL_LINK_H
+#pragma once
 
 #include "host_driver.h"
 #include <stdbool.h>
@@ -53,5 +52,3 @@ inline void serial_link_unlock(void) {}
 void signal_data_written(void);
 
 #endif
-
-#endif
diff --git a/quantum/variable_trace.h b/quantum/variable_trace.h
index 26b810d3cd2..f4d1253800c 100644
--- a/quantum/variable_trace.h
+++ b/quantum/variable_trace.h
@@ -14,8 +14,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef VARIABLE_TRACE_H
-#define VARIABLE_TRACE_H
+#pragma once
 
 // For more information about the variable tracing see the readme.
 
@@ -46,4 +45,3 @@
 void add_traced_variable(const char* name, void* addr, unsigned size, const char* func, int line);
 void remove_traced_variable(const char* name, const char* func, int line);
 void verify_traced_variables(const char* func, int line);
-#endif
diff --git a/quantum/velocikey.h b/quantum/velocikey.h
index b977606c5dc..c375f82f718 100644
--- a/quantum/velocikey.h
+++ b/quantum/velocikey.h
@@ -1,5 +1,4 @@
-#ifndef VELOCIKEY_H
-#define VELOCIKEY_H
+#pragma once
 
 #include <stdint.h>
 #include <stdbool.h>
@@ -9,5 +8,3 @@ void    velocikey_toggle(void);
 void    velocikey_accelerate(void);
 void    velocikey_decelerate(void);
 uint8_t velocikey_match_speed(uint8_t minValue, uint8_t maxValue);
-
-#endif
\ No newline at end of file
diff --git a/quantum/visualizer/common_gfxconf.h b/quantum/visualizer/common_gfxconf.h
index e5bbddbb02b..e0735b37d04 100644
--- a/quantum/visualizer/common_gfxconf.h
+++ b/quantum/visualizer/common_gfxconf.h
@@ -19,8 +19,7 @@
  * Please use spaces instead of tabs in this file.
  */
 
-#ifndef COMMON_GFXCONF_H
-#define COMMON_GFXCONF_H
+#pragma once
 
 ///////////////////////////////////////////////////////////////////////////
 // GFX - Compatibility options                                           //
@@ -353,5 +352,3 @@
 #define GMISC_NEED_MATRIXFLOAT2D GFXON
 #define GMISC_NEED_MATRIXFIXED2D GFXOFF
 //#define GMISC_NEED_HITTEST_POLY                      GFXOFF
-
-#endif /* COMMON_GFXCONF_H */
diff --git a/quantum/visualizer/default_animations.h b/quantum/visualizer/default_animations.h
index 51320b8b8a8..9accd897745 100644
--- a/quantum/visualizer/default_animations.h
+++ b/quantum/visualizer/default_animations.h
@@ -14,8 +14,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef DEFAULT_ANIMATIONS_H_
-#define DEFAULT_ANIMATIONS_H_
+#pragma once
 
 #include "visualizer.h"
 
@@ -26,5 +25,3 @@ extern keyframe_animation_t default_suspend_animation;
 // An animation for testing and demonstrating the led support, should probably not be used for real world
 // cases
 extern keyframe_animation_t led_test_animation;
-
-#endif /* DEFAULT_ANIMATIONS_H_ */
diff --git a/quantum/visualizer/lcd_backlight.h b/quantum/visualizer/lcd_backlight.h
index 0a1535edf52..4ea5b146390 100644
--- a/quantum/visualizer/lcd_backlight.h
+++ b/quantum/visualizer/lcd_backlight.h
@@ -22,8 +22,8 @@ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE.
 */
 
-#ifndef LCD_BACKLIGHT_H_
-#define LCD_BACKLIGHT_H_
+#pragma once
+
 #include <stdint.h>
 
 // Helper macros for storing hue, staturation and intensity as unsigned integers
@@ -41,5 +41,3 @@ uint8_t lcd_get_backlight_brightness(void);
 
 void lcd_backlight_hal_init(void);
 void lcd_backlight_hal_color(uint16_t r, uint16_t g, uint16_t b);
-
-#endif /* LCD_BACKLIGHT_H_ */
diff --git a/quantum/visualizer/lcd_backlight_keyframes.h b/quantum/visualizer/lcd_backlight_keyframes.h
index bde118449b6..88768dd4a50 100644
--- a/quantum/visualizer/lcd_backlight_keyframes.h
+++ b/quantum/visualizer/lcd_backlight_keyframes.h
@@ -14,8 +14,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef QUANTUM_VISUALIZER_LCD_BACKLIGHT_KEYFRAMES_H_
-#define QUANTUM_VISUALIZER_LCD_BACKLIGHT_KEYFRAMES_H_
+#pragma once
 
 #include "visualizer.h"
 
@@ -26,5 +25,3 @@ bool lcd_backlight_keyframe_set_color(keyframe_animation_t* animation, visualize
 
 bool lcd_backlight_keyframe_disable(keyframe_animation_t* animation, visualizer_state_t* state);
 bool lcd_backlight_keyframe_enable(keyframe_animation_t* animation, visualizer_state_t* state);
-
-#endif /* QUANTUM_VISUALIZER_LCD_BACKLIGHT_KEYFRAMES_H_ */
diff --git a/quantum/visualizer/lcd_keyframes.h b/quantum/visualizer/lcd_keyframes.h
index 6346c8643b4..b7125e83233 100644
--- a/quantum/visualizer/lcd_keyframes.h
+++ b/quantum/visualizer/lcd_keyframes.h
@@ -14,8 +14,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef QUANTUM_VISUALIZER_LCD_KEYFRAMES_H_
-#define QUANTUM_VISUALIZER_LCD_KEYFRAMES_H_
+#pragma once
 
 #include "visualizer.h"
 
@@ -34,5 +33,3 @@ bool lcd_keyframe_draw_logo(keyframe_animation_t* animation, visualizer_state_t*
 
 bool lcd_keyframe_disable(keyframe_animation_t* animation, visualizer_state_t* state);
 bool lcd_keyframe_enable(keyframe_animation_t* animation, visualizer_state_t* state);
-
-#endif /* QUANTUM_VISUALIZER_LCD_KEYFRAMES_H_ */
diff --git a/quantum/visualizer/led_backlight_keyframes.h b/quantum/visualizer/led_backlight_keyframes.h
index 648f92b915f..90153be5eb6 100644
--- a/quantum/visualizer/led_backlight_keyframes.h
+++ b/quantum/visualizer/led_backlight_keyframes.h
@@ -22,8 +22,7 @@ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE.
 */
 
-#ifndef LED_BACKLIGHT_KEYFRAMES_H
-#define LED_BACKLIGHT_KEYFRAMES_H
+#pragma once
 
 #include "visualizer.h"
 
@@ -39,5 +38,3 @@ bool led_backlight_keyframe_disable(keyframe_animation_t* animation, visualizer_
 bool led_backlight_keyframe_enable(keyframe_animation_t* animation, visualizer_state_t* state);
 
 extern keyframe_animation_t led_test_animation;
-
-#endif /* LED_KEYFRAMES_H */
diff --git a/quantum/visualizer/resources/resources.h b/quantum/visualizer/resources/resources.h
index 74fd8d2f652..5178fbe55a6 100644
--- a/quantum/visualizer/resources/resources.h
+++ b/quantum/visualizer/resources/resources.h
@@ -14,13 +14,10 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef QUANTUM_VISUALIZER_RESOURCES_RESOURCES_H_
-#define QUANTUM_VISUALIZER_RESOURCES_RESOURCES_H_
+#pragma once
 
 #include <stdint.h>
 
 #ifdef LCD_ENABLE
 extern const uint8_t resource_lcd_logo[];
 #endif
-
-#endif /* QUANTUM_VISUALIZER_RESOURCES_RESOURCES_H_ */
diff --git a/quantum/visualizer/visualizer.h b/quantum/visualizer/visualizer.h
index 488d130decd..627c80a305a 100644
--- a/quantum/visualizer/visualizer.h
+++ b/quantum/visualizer/visualizer.h
@@ -22,8 +22,8 @@ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE.
 */
 
-#ifndef VISUALIZER_H
-#define VISUALIZER_H
+#pragma once
+
 #include <stdlib.h>
 #include <stdint.h>
 #include <stdbool.h>
@@ -152,5 +152,3 @@ void user_visualizer_suspend(visualizer_state_t* state);
 void initialize_user_visualizer(visualizer_state_t* state);
 // Called when the computer resumes from a suspend
 void user_visualizer_resume(visualizer_state_t* state);
-
-#endif /* VISUALIZER_H */
diff --git a/quantum/visualizer/visualizer_keyframes.h b/quantum/visualizer/visualizer_keyframes.h
index 9ef7653c5e4..c92ff161136 100644
--- a/quantum/visualizer/visualizer_keyframes.h
+++ b/quantum/visualizer/visualizer_keyframes.h
@@ -14,13 +14,10 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef QUANTUM_VISUALIZER_VISUALIZER_KEYFRAMES_H_
-#define QUANTUM_VISUALIZER_VISUALIZER_KEYFRAMES_H_
+#pragma once
 
 #include "visualizer.h"
 
 // Some predefined keyframe functions that can be used by the user code
 // Does nothing, useful for adding delays
 bool keyframe_no_operation(keyframe_animation_t* animation, visualizer_state_t* state);
-
-#endif /* QUANTUM_VISUALIZER_VISUALIZER_KEYFRAMES_H_ */