Original Adidas football shirt Manchester United 2018/19

The 2018–19 season was Manchester United's 27th season in the Premier League and their 44th consecutive season in the top flight of English football. The season was the first since 2005–06 without club captain Michael Carrick, who retired after the 2017–18 season and joined the club's coaching staff. Assistant manager Rui Faria left the club at the conclusion of that season, with Carrick and Kieran McKenna replacing him as the club's first-team coaches.

A disappointing Premier League campaign saw the club finish in sixth place. United were also eliminated early in the EFL Cup, losing on penalties to Championship side Derby County in the third round. The club reached the quarter-final stage of both the FA Cup and the UEFA Champions League, but were eliminated by Wolverhampton Wanderers and Barcelona respectively. This resulted in United's first consecutive trophyless seasons in 30 years. On 5 May 2019, following a draw at bottom-placed Huddersfield Town, United confirmed their place in the 2019–20 UEFA Europa League, making it the fourth time they had finished outside of the top four in the league since 2014.

On 18 December 2018, with just seven wins in the first 17 league games, manager José Mourinho was sacked. His last game, two days earlier, ended in a 3–1 defeat to Liverpool. The following day, former United striker Ole Gunnar Solskjær was appointed as caretaker manager until the end of the season, assisted by former coach Mike Phelan, who had left the club in 2013 following the retirement of Sir Alex Ferguson. On 28 March 2019, Solskjær became full-time manager.