Alexis Mac Allister (born 24 December 1998) is an Argentine professional footballer who plays as a midfielder for Premier League club Liverpool and the Argentina national team.

He joined Brighton & Hove Albion in 2019 but was immediately loaned back to them until the end of the season and later to rivals Boca Juniors, where he won the 2019–20 Primera División.

Returning from the loan the following season, Mac Allister had his breakthrough year for Brighton, becoming a key player for the team, before moving to Liverpool in June 2023.

He made his senior international debut in 2019 and was part of the Argentina squads that won the 2022 Finalissima, 2022 FIFA World Cup and 2024 Copa América.

[12] Like his two brothers, Mac Allister started his career with Club Social y Deportivo Parque before joining Argentinos Juniors' youth setup.

[13] He made his first-team debut on 30 October 2016, coming on as a second-half substitute for Iván Colman in a 0–0 Primera B Nacional home draw against Central Córdoba.

[16] On 25 November 2017, Mac Allister and his two brothers all played together for the first time in a 1–0 loss at San Lorenzo; Alexis and Francis were starters, while Kevin came on as a substitute.

[20][21] Mac Allister scored on his Boca debut, with the team's only goal in the first leg of a Copa Libertadores round of sixteen victory over Athletico Paranaense on 25 July.

[34] Mac Allister provided Adam Webster's headed equaliser from a corner in a 1–1 home draw against the European champions, Chelsea, on 18 January.

On 7 January, Mac Allister scored a brace in a 5–1 away win over EFL Championship team Middlesbrough in the third round of the 2022–23 FA Cup.

[42][43] On 14 January, his first return to Brighton's Falmer Stadium since the World Cup, Mac Allister wore his winner's medal as he walked out onto the pitch ahead of the match against Liverpool.

[58] On 19 August, Mac Allister received a red card for a foul against Ryan Christie during a Premier League home match against Bournemouth.

[65][66] On 24 September 2023, Mac Allister provided his first competitive assist for Liverpool with a long clipped ball for Darwin Núñez in a 3–1 victory against West Ham United.

[67] On 5 October, he shared the pitch with his brother Kevin after the former came on as a substitute in the 46th minute in a Europa League group stage match against Union Saint-Gilloise.

[73] On his time under manager Jürgen Klopp's final season, Mac Allister added "I played as a lone five [holding midfielder].

[76] On 26 December, Mac Allister provided 2 assists for Cody Gakpo and Curtis Jones as Liverpool came from behind to beat Leicester City 3-1 in the Premier League.

[91] After Argentina made the final, Mac Allister started the match against defending champions France where he assisted Ángel Di María's goal to make the score 2–0.

[93] He played in all but one of their matches and recorded two assists as they went on to win the tournament, defeating Colombia 1–0 in the final and earning Mac Allister his third senior international trophy in as many years.