Unai Simón Mendibil is a Spanish professional footballer who plays as a goalkeeper for the Spain national team. Simón was born in Vitoria-Gasteiz, Álava, Basque Country, and joined Athletic Bilbao’s youth system in 2011, from CD Aurrerá de Vitoria. He made his debut as a senior with the farm team in the 2014–15 season, in Tercera División. On 8 June 2016, Simón was promoted to the reserves, freshly relegated to Segunda División B. He immediately became a starter for the side, contributing with 29 appearances during the campaign. On 2 June 2017, Simón was called up to the main squad for the pre-season by new first team manager José Ángel Ziganda, but continued to appear exclusively for the Bs. On 13 July 2018, he signed a contract extension until 2023, and was loaned to Segunda División side Elche CF two weeks later. On 15 August 2018, after Kepa Arrizabalaga’s departure from the club and Iago Herrerín’s injury, Simón was recalled by Athletic.