B
| Class | Country | Type | Launch years | Displacement (tons) | Number |
| B | Brazil | destroyer | 1930 | 1,360 | 9 |
| B | UK | destroyer | 1943 | 1,253 | 8 |
| B | Norway | submarine | 1923-29 | 365 | 6 |
| Bahia | Brazil | scout cruiser | 1910 | 3,100 | 2 |
| Bagley | US | destroyer | 1936-37 | 1,646 | 8 |
| Balao | US | submarine | 1,826 | 132 | |
| Baltimore | US | heavy cruiser | 1942-51 | 14,472 | 19 |
| Bangor | UK | minesweeper | 1940-44 | 600 | 128 |
| Bathurst | Australia India |
corvette | 1,025 | 60 | |
| Battle | UK | destroyer | 1943-45 | 2,315-2,574 | 24 (42 planned) |
| Benham | US | destroyer | 1938-39 | 1,637 | 10 |
| Benson = Gleaves | US | destroyer | 1939-41 | 1,839 | 24 |
| Bird | UK | minesweeper | c1938-40 | 607 | 45 |
| Bismarck | Germany | battleship | 1939 | 51,700 | 2 |
| Black Swan (including modified Black Swans) | UK India |
sloop | 1939-45 | 1,250 | 37 |
| Bogue = Attacker = Ruler | US | escort aircraft carrier | 16,000 | 42 | |
| Bourrasque = 1500 tonnes | France | destroyer | 1924-25 | 1,298 | 12 |
| Bretagne | France | battleship | 1913 | 22,200 | 3 |
| Bristol | US | destroyer | 1941-43 | 1,839 | 72 |
| Brin | Italy | submarine | 1,016 | 5 | |
| Brooklyn | US | light cruiser | 1936-38 | 9,767 | 9 |
Read more about this topic: List Of World War II Ship Classes