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.
Born to a footballing family, Mac Allister started his senior career with Argentinos Juniors in 2016, winning the Argentine second division in his debut season. He joined Brighton & Hove Albion in 2019 but was immediately loaned back to Juniors until the end of the season. During his second year at Brighton, he was again loaned to Argentina to 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. He was their top scorer in the 2022–23 season.
Mac Allister represented Argentina at under-23 level, winning the 2020 CONMEBOL Pre-Olympic Tournament and playing at the 2020 Summer Olympics. He made his senior international debut in 2019 and was part of the Argentina squad that won the 2022 Finalissima with a 3–0 victory against Italy. He was part of the Argentina team that won the 2022 FIFA World Cup and he assisted a goal in the final against France.