Combat air patrol (CAP) is a type of defensive mission for fighter aircraft, in which they guard a designated site, either a fixed site on land, ships at sea, or less commonly support aircraft such as aerial tankers.

It typically entails fighters flying some sort of pattern around the defended object, while looking for incoming attackers. Effective CAP patterns may include aircraft positioned at both high and low altitudes, so as to shorten response times when the attack is detected.

CAP is especially characteristic of aircraft carrier operations.

The real-life activity inspired the computer game Combat Air Patrol, a flight simulator published by Psygnosis in 1995.