| Name | Meaning | Gender | Origin |
|---|
| Blackie | Of the colour black. | Unisex | English |
| Blu | | Unisex | Hebrew |
| Blue | Blue | Unisex | English |
| Bo | Handsome | Female | French |
| Bob | Bright fame | Male | Germanic |
| Bobbie | Bright fame | Female | Germanic |
| Bobby | Bright fame | Unisex | Germanic |
| Bogey | | Unisex | Hebrew |
| Bolt | | Unisex | Hebrew |
| Bongo | Connected drums played by beating with hands. | Unisex | English |
| Boomer | A large full grown kangaroo. A baby boomer. | Unisex | English |
| Boris | Battle, fight | Male | Slavonic |
| Bossy | | Unisex | Hebrew |
| Boston | Botolph's town | Unisex | English |
| Brandon | Broom hill | Male | English |
| Brian | Noble, strong, virtuous | Male | Gaelic |
| Bruiser | A large heavyset man | Unisex | English |
| Bruno | Armour | Male | Germanic |
| Brutus | Heavy, slow, foolish | Male | Latin |
| Bubba | | Unisex | Hebrew |
| Buck | He-goat | Male | English |
| Buckles | | Unisex | Hebrew |
| Buddy | Herald | Male | English |
| Bullet | A metal cylinder shot from a rifle or gun. Used to express speed. | Unisex | English |
| Bumper | | Unisex | Hebrew |
| Buster | One that breaks up something | Unisex | American English |
| Butch | Masculine in appearance or manner. | Unisex | American English |
| Buttons | | Unisex | Hebrew |
| Caesar | Long Hair | Male | Latin |
| Cam | Man with crooked nose | Female | Gaelic |