B4
- 203-mm howitzer M1931 (B-4)
- 4B (disambiguation)
- Alekhine's Defence
- Alpina B4
- Alsace-Lorraine B 4
- Auster B.4
- B-4 (Star Trek)
- B4 (New York City bus)
- B4 (TV channel)
- B4 (classification)
- B4 (music show)
- B4 Championships
- B4 road (Namibia)
- B4-mount
- BIV (disambiguation)
- Babylon 4
- Bavarian B IV
- BeOnd
- Before (disambiguation)
- Bensen Aircraft
- Bundesstraße 4
- Bäumer Sausewind
- Flyglobespan
- Fokker F.11
- GSR Class B4
- HMS B4
- Hawker Hart
- Keystone B-4
- LNER Class B4
- LSWR B4 class
- Leukotriene B4 receptor
- Lipoxin B4
- Lohner B.IV
- Native Instruments
- Pennsylvania Railroad
- Pilatus B-4
- Proanthocyanidin B4
- SM UB-4
- Sokolsky Opening
- Soo Line B-4 class
- Subaru Legacy
- Vitamin B4