Cornerback is a defensive position in American football.

On the defense, the cornerback is a member of the secondary. While football coaches can dictate any role for a defensive player, cornerbacks are often charged with "covering" the opposition wide receiver--that is, preventing the other team from catching the ball in a pass.

In the NFL, cornerbacks are often chosen for their speed and coverage ability.

Statistics for cornerbacks include interceptions, tackles, and deflected passes.