P
| Class | Country | Type | Launch years | Displacement (tons) | Number |
| P611 | UK | submarine | 1940 | 856 | 4 |
| Parthian | UK | submarine | 1929 | 2,040 submerged | 6 |
| Pennsylvania | US | battleship | 33,000 | 2 | |
| Pensacola | US | heavy cruiser | 1929 | 9,100 | 2 |
| Pichincha | Colombia | coast guard vessel | 120 | 3 | |
| Poltava | USSR | battleship | 25,000+ | 9 | |
| Porpoise | US | submarine | 1,310 | ||
| Porter | US | destroyer | 1936-37 | 1,834 | 8 |
| Portland | US | heavy cruiser | 1931-32 | 10,258 | 2 |
| Proussa | Greece | torpedoboat | 1915-16 | 266 | 2 |
Read more about this topic: List Of World War II Ship Classes