is an Argentine professional footballer who plays as a forward for and captains both Major League Soccer club Inter Miami and the Argentina national team. Widely regarded as one of the greatest players of all time, Messi set numerous records for individual accolades won throughout his professional footballing career such as eight Ballon d'Or awards and eight times being named the world's best player by FIFA. He is the most decorated player in the history of professional football having won 45 team trophies, including twelve Big Five league titles, four UEFA Champions Leagues, two Copa Américas, and one FIFA World Cup. Messi holds the records for most European Golden Shoes (6), most goals in a calendar year (91), most goals for a single club (672, with Barcelona), most goals (474), hat-tricks (36) and assists (192) in La Liga, most assists (18) and goal contributions (32) in the Copa América, most goal contributions (21) in the World Cup, most international appearances (191) and international goals (112) by a South American male, and the second-most in the latter category outright. A prolific goalscorer and creative playmaker, Messi has scored over 850 senior career goals and has provided over 380 assists for club and country.

Born in Rosario, Argentina, Messi relocated to Spain to join Barcelona at age 13, and made his competitive debut at age 17 in October 2004. He gradually established himself as an integral player for the club, and during his first uninterrupted season at age 22 in 2008–09 he helped Barcelona achieve the first treble in Spanish football. This resulted in Messi winning the first of four consecutive Ballons d'Or, and by the 2011–12 season he would set La Liga and European records for most goals in a season and establish himself as Barcelona's all-time top scorer. The following two seasons, he finished second for the Ballon d'Or behind Cristiano Ronaldo, his perceived career rival. However, he regained his best form during the 2014–15 campaign, where he became the all-time top scorer in La Liga, led Barcelona to a historic second treble, and won a fifth Ballon d'Or in 2015. He assumed Barcelona's captaincy in 2018 and won a record sixth Ballon d'Or in 2019. During his overall tenure at Barcelona, Messi won a club-record 34 trophies, including ten La Liga titles and four Champions Leagues, among others. Financial difficulties at Barcelona led to Messi signing with French club Paris Saint-Germain in August 2021, where he would win the Ligue 1 title during both of his seasons there. He joined Major League Soccer club Inter Miami in July 2023.

An Argentine international, Messi is the national team's all-time leading goalscorer and most-capped player. His style of play as a diminutive, left-footed dribbler, drew career-long comparisons with compatriot Diego Maradona, who described Messi as his successor. At the youth level, he won the 2005 FIFA World Youth Championship and gold medal in the 2008 Summer Olympics. After his senior debut in 2005, Messi became the youngest Argentine to play and score in a World Cup in 2006. Assuming captaincy in 2011, he then led Argentina to three consecutive finals in the 2014 FIFA World Cup, the 2015 Copa América and the Copa América Centenario, all of which they would lose. After initially announcing his international retirement in 2016, he returned to help his country narrowly qualify for the 2018 FIFA World Cup, which they would exit early. Messi and the national team finally broke Argentina's 28-year trophy drought by winning the 2021 Copa América, which helped him secure his seventh Ballon d'Or that year. He then led Argentina to win the 2022 Finalissima, as well as the 2022 FIFA World Cup, his country's third overall world championship and first in 36 years. This followed with a record-extending eighth Ballon d'Or in 2023, and a victory in the 2024 Copa América.

Messi has endorsed sportswear company Adidas since 2006. According to France Football, he was the world's highest-paid footballer for five years out of six between 2009 and 2014, and was ranked the world's highest-paid athlete by Forbes in 2019 and 2022. Messi was among Time's 100 most influential people in the world in 2011, 2012, and 2023. In 2020 and 2023, he was named the Laureus World Sportsman of the Year, the first team-sport athlete to win it. In 2020, Messi was named to the Ballon d'Or Dream Team and became the second footballer and second team-sport athlete to surpass $1 billion in career earnings. Following his arrival and impact on football in the US, Messi was named Time's Athlete of the Year in 2023, and was bestowed with the Presidential Medal of Freedom by US president Joe Biden in 2025.