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