Arsenal F.C.–Manchester United F.C. rivalry

Although Arsenal and Manchester United have frequently been in the same division in English football since 1919, the rivalry between the two clubs only became a fierce one in the late 1990s and early 2000s, when the teams regularly competed against each other for the Premier League title and FA Cup. There was also an enmity between the managers, Arsenal's Arsène Wenger (1996–2018) and United's Sir Alex Ferguson (1986–2013), and club captains Patrick Vieira and Roy Keane, and their contests often involved on-field trouble – seven red cards were shown in matches from February 1997 to February 2005. The league fixture in September 2003, known as the "Battle of Old Trafford", was marred by a mêlée instigated by Arsenal players, who felt striker Ruud van Nistelrooy had cheated to get Vieira sent off. A season later, Manchester United ended Arsenal's unbeaten run in controversial circumstances, which led to more disorder, this time in the tunnel. Manchester United lead in trophies won with 67 honours compared to Arsenal's 48.

By 2008, former Arsenal player Lee Dixon noted that the rivalry had diminished. Ferguson also stated that the two teams' meetings had cooled from their previous "heated" exchanges. Other factors for the diminishing importance of the rivalry in the 2010s were the ascendancy of other clubs, including local rivals of both (Chelsea, Tottenham Hotspur and Manchester City).

Arsenal and Manchester United first played a competitive match in October 1894; as of 3 September 2023, the clubs have faced each other 240 times, with United winning 99 games to Arsenal's 88, and 53 matches drawn. Wayne Rooney scored the most goals (12), while Ryan Giggs made the highest number of appearances (50). Several players have featured for both clubs at different stages of their career, including Brian Kidd, Andy Cole, David Platt, Robin van Persie, Danny Welbeck, Alexis Sánchez and former manager George Graham.