Fullback or Full back may refer to:
In sports:
- A position in various kinds of football, including:
- Full back (association football), in association football (soccer), a defender playing in a wide position
- Fullback (American football), in American football (gridiron), a position in the offensive backfield
- Fullback (Australian rules football), in Australian rules football, a defensive position
- Fullback (rugby league), a position behind the main line of backs
- Fullback, one of the rugby union positions
- A similar defence position in (field) hockey
In other uses:
- Sukhoi Su-34, a Russian fighter aircraft, from its NATO reporting name