U-451
| Type: | VIIC |
| Laid down: | 18th May 1940. |
| Built at: | Deutsche Werke, Kiel. |
| Commissioned: | 3rd May 1941. |
| Commanders: | 3rd May 1941 - 21st December 1941 - HrvKpt. Eberhard Hoffmann. |
| Career: | 4 patrols. 3rd May 1941 - 1st July 1941, 3rd Flottille (Training). 1st July 1941 - 21st December 1941, 3rd Flottille (Front Boat). |
| Successes: | 1 ship sunk for a total of 441 tons. |
| Fate: | Sunk 21st December 1941 near Tangiers, in position 35.55N, 06.08W, by depth charges from a British Swordfish aircraft (Sqdn. 812/A). 44 dead and 1 survivor. |
| Notes: | 3rd Flottille had a total of 109 U-boats from March 1941 to October 1944. |

Type VIIC German U-boat.