| Name | Meaning | Gender | Origin |
|---|
| Bilbo | | Unisex | Hebrew |
| Binky | | Unisex | Hebrew |
| Biscuit | A cookie or cracker | Unisex | English |
| Black | Dark | Unisex | English |
| Blackie | Of the colour black. | Unisex | English |
| Blackjack | A leather covered hand weapon. A card game | Unisex | English |
| Blaze | Stuttering | Unisex | Latin |
| Blazer | | Unisex | Hebrew |
| Blizzard | Violent snowstorm | Unisex | English |
| Blu | | Unisex | Hebrew |
| Blue | Blue | Unisex | English |
| Bojangles | | Unisex | Hebrew |
| Bongo | Connected drums played by beating with hands. | Unisex | English |
| Bonsai | The art of growing dwarfed ornamental trees and shrubs. | Unisex | English |
| Boo | | Unisex | Hebrew |
| Booger | | Unisex | Hebrew |
| Brady | Descendant of Brádach | Unisex | Gaelic |
| Bruiser | A large heavyset man | Unisex | English |
| Bubba | | Unisex | Hebrew |
| Bubble | | Unisex | Hebrew |
| Bubbles | Thin spherical liquid filled with gas. Irrepressible activity. | Unisex | English |
| Buckwheat | | Unisex | Hebrew |
| Bugsy | | Unisex | Hebrew |
| Bull | The adult male of certain large animals like cattle and elephants | Unisex | 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 |
| Buttercup | A bright yellow flowered plant. Also a term of endearment. | Unisex | English |
| Buttons | | Unisex | Hebrew |