The 1970–71 FA Cup was the 90th season of the world's oldest football cup competition, the Football Association Challenge Cup, commonly known as the FA Cup. First Division champions Arsenal won the competition for the fourth time, beating Liverpool 2–1 in the final at Wembley. In doing so, Arsenal were the fourth team to complete a double of League and Cup victories, following Preston North End, Aston Villa and Tottenham Hotspur.

Matches were scheduled to be played at the stadium of the team named first on the date specified for each round, which was always a Saturday. Some matches, however, might be rescheduled for other days if there were clashes with games for other competitions or the weather was inclement. If scores were level after 90 minutes had been played, a replay would take place at the stadium of the second-named team later the same week. If the replayed match was drawn further replays would be held until a winner was determined. If scores were level after 90 minutes had been played in a replay, a 30-minute period of extra time would be played.

The rights to show FA Cup games were, as with Football League matches, shared between the BBC and ITV network. All games were shown in a highlights format, except the Final, which was shown live both on BBC1 and ITV. The BBC football highlights programme Match Of The Day would show up to three games and the various ITV regional network stations would cover up to one game and show highlights from other games covered elsewhere on the ITV network. The ITV region Anglia showed highlights of the second round tie between Colchester United and Cambridge United, it would be the last game from outside the third round covered by ITV until 1982. Highlights of replays would be shown on either the BBC or ITV.

• 1970–71 WFA Cup