Jon Gaztañaga Arrospide (born 28 June 1991) is a Spanish professional footballer who plays as a central defender or a defensive midfielder for fifth-tier Tercera Federación club Beasain.

Gaztañaga made his official debut with the first team on 18 August 2013, replacing fellow youth graduate Gorka Elustondo in the dying minutes of the 2–0 La Liga home win against Getafe CF.

[2] His first appearance in the UEFA Champions League took place on 10 December, as he came on for Mikel González in a 0–1 group-stage defeat to Bayer 04 Leverkusen also at the Anoeta Stadium.

[5] On 26 January 2015, having featured sparingly during the first half of the campaign, he joined Segunda División club SD Ponferradina on loan until June.

[12] On 24 June 2021, he returned to Spain and joined Cultural y Deportiva Leonesa of the newly created Primera División RFEF.