Original Nike trainingsshirt Manchester United 2012/13

The 2012–13 season was Manchester United's 21st season in the Premier League, and their 38th consecutive season in the top flight of English football.

United's season began on 20 August 2012 with the first game of the Premier League campaign. After narrowly missing out on goal difference the previous season, they won an unprecedented 20th English top-flight title on 22 April 2013 with a win over Aston Villa at Old Trafford, in which top scorer Robin van Persie scored a hat-trick, finishing the season with 26 league goals and 30 goals in all competitions.

United competed in two domestic cups, the FA Cup and the League Cup, where they entered both tournaments in the Third Round courtesy of their league position. Chelsea proved to be United's nemesis in both competitions, first beating them 5–4 in the Fourth Round of the League Cup on 31 October 2012, followed by a 1–0 win in the FA Cup Sixth Round Replay on 1 April 2013.

In Europe, United were knocked out of the Champions League at the Round of 16 stage after losing 3–2 on aggregate to Real Madrid.

On 8 May 2013, United's long time manager, Sir Alex Ferguson announced that he would retire from his position as manager of Manchester United after 26+1⁄2 years in charge, making him the longest-serving manager of any English club by this stage. He had won 38 trophies during that time – more than any other manager in the history of football – and at 71 was the oldest serving manager currently in the Premier League or Football League.

The next day, Manchester United announced that David Moyes of Everton would take over from Ferguson at the beginning of the 2013–14 season.