Bo may be:
- An east Asian quarterstaff, see bo (weapon)
- A tree, see peepul
- A city in Sierra Leone, see Bo, Sierra Leone
- ISO country code for Bolivia
- Bo is the UIC classification for the railroad locomotive wheel arrangement known as 0-4-0 in the Whyte notation; a locomotive with two powered axles (and thus four wheels) in which the axles are independently powered (e.g. by seperate traction motors)
- Bø, Telemark and Bø, Nordland, two municipalities in Norway.