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.

At this stage clubs from the Football League Third and Fourth Divisions joined those non-league clubs having come through the qualifying rounds. Matches were scheduled to be played on Saturday, 21 November 1970, with the exception of the Great Harwood–Rotherham United match, which was played the following Tuesday. Nine matches were drawn, of which one went to a second replay.

The matches were scheduled for Saturday, 12 December 1970. Six matches were drawn, with replays taking place later the same week or the week after. The Lincoln City–Bradford City match required a second replay, which was played on the 21 December.

The 44 First and Second Division clubs entered the competition at this stage. The matches were scheduled Saturday, 2 January 1971, but ten were played at later dates. Seven matches were drawn and went to replays.

The matches were scheduled for Saturday, 23 January 1971. Seven matches were drawn, of which one required a second replay.

The matches were scheduled for Saturday, 13 February 1971 with one fixture and two replays played three or four days later.

The four sixth round ties were played on the 6 March 1971. There were two replays in the midweek fixtures of the following week.

The semi-final matches were played on Saturday, 27 March 1971 with the Arsenal–Stoke match needing a replay. Liverpool and Arsenal came through the Semi final round to meet at Wembley.

Between 1970 and 1974, a third place playoff between the two losing semi-finalists was held.^[1]

The 1971 FA Cup Final was contested by Arsenal and Liverpool at Wembley on the 8 May 1971. Arsenal won 2–1 after extra time, with all three goals coming in the added half-hour. Steve Heighway scored for Liverpool first, before Arsenal equalised with a scrambled goal from substitute Eddie Kelly - the first time a substitute had ever scored in an FA Cup final. Charlie George scored the winner in extra time.

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 1984. Highlights of replays would be shown on either the BBC or ITV.