Ander Barrenetxea Muguruza (born 27 December 2001) is a Spanish professional footballer who plays as a forward or left winger. Born in San Sebastián, Gipuzkoa, Basque Country, he's a graduate of Real Sociedad's youth setup. In the 2018/19 season, he began to become involved in training with the senior team, while registered with the club's C-team playing in the amateur fourth tier. In early December 2018, he renewed his contract until 2025. On 22 December 2018, Barrenetxea made his professional and La Liga debut for Real Sociedad in a 1–0 home loss against Deportivo Alavés. In so doing, he became the first player born in the 21st century to appear in the competition, the 26th-youngest debutant in the division overall, and the club's youngest since the Spanish Civil War.