S
| Class | Country | Type | Launch years | Displacement (tons) | Number |
| S | UK | submarine | 1931–1945 | c. 950 | 63 |
| S | US | submarine | 900 | 48 | |
| S and T | UK | destroyer | 1942-43 | 1,710 | 16 |
| Salmon | US | submarine | 1,430 | 6 | |
| Sangamon | US | escort aircraft carrier | 11,400 | 4 | |
| Sargo | US | submarine | 1,450 | 10 | |
| Sborul | Romania | torpedoboat | 1914 | 262 | 1 |
| Scharnhorst = Gneisenau | Germany | battleship | 1936 | 31,840 | 2 |
| Schleswig-Holstein | Germany | modernized pre-dreadnought | 1906 | 12,100 | 2 (at outbreak of World War II) |
| Sendai | Japan | light cruiser | 1923-25 | 5,113 | 3 completed |
| Serrano | Chile | destroyer | 1928 | 1,090 | 6 |
| Sims | US | destroyer | 1938-39 | 1,764 | 12 |
| Shimakaze | Japan | destroyer | 1942 | 2,567 | 1 completed |
| Shimane Maru | Japan | escort aircraft carrier | 1944 | 11,800 | 1 completed |
| Shiratsuyu | Japan | destroyer | 1935-37 | 1,685 | 10 |
| Sleipner | Norway | destroyer | 1936-38 | 597 | 3 |
| Søbjørnen | Denmark | minesweeper | 270 | 6 | |
| Soldati | Italy | destroyer | 1937-42 | 1,620 | 19 |
| Somers | US | destroyer | 1937-38 | 2,047 | 5 |
| South Dakota | US | battleship | 1941-42 | 37,970 | 4 |
| Southampton: sub-class of Town | UK | light cruiser | 1936 | 9,100 | 5 |
| Spica | Italy | torpedoboat | 1936-38 | 640 | 30 |
| Suffren | France | heavy cruiser | 1927-30 | 9,940 | 4 |
| Sumner = Allen M Sumner | US | destroyer | 1943-44 | 2,610 | 70 |
Read more about this topic: List Of World War II Ship Classes