diff --git a/Marlin/src/HAL/HAL_TEENSY31_32/HAL_timers_Teensy.h b/Marlin/src/HAL/HAL_TEENSY31_32/HAL_timers_Teensy.h
index 35af9feba..52d4965e3 100644
--- a/Marlin/src/HAL/HAL_TEENSY31_32/HAL_timers_Teensy.h
+++ b/Marlin/src/HAL/HAL_TEENSY31_32/HAL_timers_Teensy.h
@@ -26,8 +26,6 @@
  * Teensy3.2 (__MK20DX256__)
  */
 
-#pragma once
-
 #include <stdint.h>
 
 // ------------------------
diff --git a/Marlin/src/HAL/HAL_TEENSY31_32/endstop_interrupts.h b/Marlin/src/HAL/HAL_TEENSY31_32/endstop_interrupts.h
index 1af89e0f3..743f91781 100644
--- a/Marlin/src/HAL/HAL_TEENSY31_32/endstop_interrupts.h
+++ b/Marlin/src/HAL/HAL_TEENSY31_32/endstop_interrupts.h
@@ -35,8 +35,6 @@
  * (Located in Marlin/buildroot/share/pin_interrupt_test/pin_interrupt_test.ino)
  */
 
-#pragma once
-
 #include "../../module/endstops.h"
 
 // One ISR for all EXT-Interrupts
diff --git a/Marlin/src/HAL/HAL_TEENSY31_32/fastio_Teensy.h b/Marlin/src/HAL/HAL_TEENSY31_32/fastio_Teensy.h
index 7bcd601b5..d1b5f567d 100644
--- a/Marlin/src/HAL/HAL_TEENSY31_32/fastio_Teensy.h
+++ b/Marlin/src/HAL/HAL_TEENSY31_32/fastio_Teensy.h
@@ -27,8 +27,6 @@
  * Contributed by Triffid_Hunter and modified by Kliment, thinkyhead, Bob-the-Kuhn, et.al.
  */
 
-#pragma once
-
 #ifndef MASK
   #define MASK(PIN) (1 << PIN)
 #endif
diff --git a/Marlin/src/HAL/shared/servo.h b/Marlin/src/HAL/shared/servo.h
index b6b2d13e9..96644ee26 100644
--- a/Marlin/src/HAL/shared/servo.h
+++ b/Marlin/src/HAL/shared/servo.h
@@ -67,8 +67,6 @@
  *                   With DEACTIVATE_SERVOS_AFTER_MOVE wait SERVO_DELAY and detach.
  */
 
-#pragma once
-
 #if IS_TEENSY32
   #include "../HAL_TEENSY31_32/HAL_Servo_Teensy.h"
 #elif IS_TEENSY35 || IS_TEENSY36
diff --git a/Marlin/src/feature/Max7219_Debug_LEDs.h b/Marlin/src/feature/Max7219_Debug_LEDs.h
index eeb38e8fa..02f7c1888 100644
--- a/Marlin/src/feature/Max7219_Debug_LEDs.h
+++ b/Marlin/src/feature/Max7219_Debug_LEDs.h
@@ -41,7 +41,6 @@
  * faster to do a Max7219_Set_Column() with a rotation of 90 or 270 degrees than to do
  * a Max7219_Set_Row().    The opposite is true for rotations of 0 or 180 degrees.
  */
-#pragma once
 
 #ifndef MAX7219_ROTATE
   #define MAX7219_ROTATE 0
diff --git a/Marlin/src/gcode/gcode.h b/Marlin/src/gcode/gcode.h
index 8de0f65a4..9a90c5df4 100644
--- a/Marlin/src/gcode/gcode.h
+++ b/Marlin/src/gcode/gcode.h
@@ -274,7 +274,6 @@
  * T0-T3 - Select an extruder (tool) by index: "T<n> F<units/min>"
  *
  */
-#pragma once
 
 #include "../inc/MarlinConfig.h"
 #include "parser.h"
diff --git a/Marlin/src/lcd/extensible_ui/ui_api.h b/Marlin/src/lcd/extensible_ui/ui_api.h
index 6cffefe51..5cae33a28 100644
--- a/Marlin/src/lcd/extensible_ui/ui_api.h
+++ b/Marlin/src/lcd/extensible_ui/ui_api.h
@@ -42,8 +42,6 @@
  *   location: <http://www.gnu.org/licenses/>.                              *
  ****************************************************************************/
 
-#pragma once
-
 #include "../../inc/MarlinConfig.h"
 
 namespace ExtUI {
diff --git a/Marlin/src/libs/vector_3.h b/Marlin/src/libs/vector_3.h
index 0a986374d..b56e1d60b 100644
--- a/Marlin/src/libs/vector_3.h
+++ b/Marlin/src/libs/vector_3.h
@@ -40,8 +40,6 @@
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  */
 
-#pragma once
-
 class matrix_3x3;
 
 struct vector_3 {
diff --git a/Marlin/src/module/delta.h b/Marlin/src/module/delta.h
index aa842fb02..24af5daa3 100644
--- a/Marlin/src/module/delta.h
+++ b/Marlin/src/module/delta.h
@@ -25,8 +25,6 @@
  * delta.h - Delta-specific functions
  */
 
-#pragma once
-
 extern float delta_height,
              delta_endstop_adj[ABC],
              delta_radius,
diff --git a/Marlin/src/module/motion.h b/Marlin/src/module/motion.h
index 35819187a..1d2ccf110 100644
--- a/Marlin/src/module/motion.h
+++ b/Marlin/src/module/motion.h
@@ -27,7 +27,6 @@
  * High-level motion commands to feed the planner
  * Some of these methods may migrate to the planner class.
  */
-#pragma once
 
 #include "../inc/MarlinConfig.h"
 
diff --git a/Marlin/src/module/scara.h b/Marlin/src/module/scara.h
index 44f07026e..3a17cddbf 100644
--- a/Marlin/src/module/scara.h
+++ b/Marlin/src/module/scara.h
@@ -25,8 +25,6 @@
  * scara.h - SCARA-specific functions
  */
 
-#pragma once
-
 #include "../core/macros.h"
 
 extern float delta_segments_per_second;
diff --git a/Marlin/src/pins/stm32/pins_BLACK_STM32F407VE.h b/Marlin/src/pins/stm32/pins_BLACK_STM32F407VE.h
index a0b8f8709..3edc77460 100644
--- a/Marlin/src/pins/stm32/pins_BLACK_STM32F407VE.h
+++ b/Marlin/src/pins/stm32/pins_BLACK_STM32F407VE.h
@@ -27,8 +27,6 @@
  * Shield - https://github.com/jmz52/Hardware
  */
 
-#pragma once
-
 #if !defined(STM32F4) && !defined(STM32F4xx)
   #error "Oops! Select an STM32F4 board in 'Tools > Board.'"
 #elif HOTENDS > 2 || E_STEPPERS > 2