Knock-on may refer to:
* Rugby terminology:
**
Knock-on (rugby league), error by the player in possession of the ball in rugby league football
**
Knock-on (rugby union), event where the ball is knocked forward in rugby union
* Causality-related terms:
**
Knock-on electron
**
Knock-on effect
See also
*
Fumble
A fumble in gridiron football occurs when a player who has possession and control of the ball loses it before being downed (tackled), scoring, or going out of bounds. By rule, it is any act other than passing, kicking, punting, or successful h ...
{{disambig