Jacob Harry Maguire (born 5 March 1993) is an English professional footballer who plays as a centre-back for Premier League club Manchester United and the England national team.

Maguire came through the youth system at Sheffield United before graduating to the first team in 2011. He made 166 appearances for United and was the club's Player of the Year three seasons in succession, also featuring in the PFA Team of the Year for League One as many times. In 2014, he transferred to Hull City for £2.5 million, before being loaned to Wigan Athletic in 2015. He joined Leicester City in 2017 for an initial fee of £12 million and in the 2017–18 season he played in every minute and was named Player of the season. Maguire moved to Manchester United in 2019 for a fee believed to be £80 million, a world-record amount for a defender, and within six months was appointed club captain, a role he held until 2023.

Maguire played one match for the England national under-21 team in 2012. He made his senior debut in 2017, and was chosen for the England squads for the 2018 and 2022 FIFA World Cups, and for UEFA Euro 2020. He earned a place in the Team of the Tournament in the latter.

Jacob Harry Maguire was born on 5 March 1993 in Sheffield, South Yorkshire, and was raised in the nearby village of Mosborough. His brothers, Joe and Laurence, are also footballers. He attended Immaculate Conception Catholic Primary School in Spinkhill and St Mary's Roman Catholic High School in Chesterfield. From 7 to 16 years old, Maguire played as central midfielder for Sheffield United's academy.

After coming through the youth system at Sheffield United, and with the team struggling against relegation, Maguire was promoted to the first-team squad, making his debut after coming on as a half-time substitute and winning the Man of the Match award in a home match against Cardiff City in April 2011. He made four further appearances that season but could not prevent the club from being relegated to League One.

Having cemented his place in the first team, Maguire scored his first goal for United in a 2–0 win away Oldham Athletic on the opening day of the 2011–12 League One season. Having been ever-present from the start of the season Maguire was handed an extended deal in October to keep him at Bramall Lane until 2015. He continued in great form as United pushed for promotion from League One and was rewarded at the end of the season when he was named as both "Player of the Year" and "Young Player of the Year" by the club. The BBC's Match of the Day magazine selected Maguire in its League One Team of The Year for 2011–12. He was also named in the PFA Team of the Year that season for League One.

Maguire went into the following season as first choice in the centre of defence and his good form continued as he scored twice on 17 October 2012 in a 4–1 away victory over Notts County in the Football League Trophy. By the end of February 2013, Maguire had made his 100th start for United in a 0–0 home draw against Leyton Orient at the age of just 19. His performances during the 2012–13 and 2013–14 seasons earned him a place in the PFA Team of the Year for League One again.

On 21 June 2014, it was revealed that United had offered Maguire an improved contract amid interest from Hull City and Wolverhampton Wanderers, with United already rejecting a £1 million and an improved £1.5 million bid from Wolves.