|Full name||Jon Iñaki Aspiazu San Emeterio|
|Date of birth||5 November 1962|
|Place of birth||Bilbao, Spain|
|Height||1.72 m (5 ft 8 in)|
|1987–1992||Deportivo La Coruña||134||(8)|
|2002–2003||Bilbao Athletic (assistant)|
|2003–2005||Athletic Bilbao (assistant)|
|2013–2017||Athletic Bilbao (assistant)|
|* Senior club appearances and goals counted for the domestic league only|
Aspiazu made his first team debut on 19 May 1984, starting in a 1–3 home loss against Atlético Madrid, for the year's Copa de la Liga. In July, he moved to fellow La Liga team Hércules CF, but featured rarely; his debut in the category occurred on 18 November 1984, in a 1–1 home draw against Sporting de Gijón.
In 1985 Aspiazu joined Segunda División side Sestao Sport Club, being an undisputed starter during his two-year spell at the club. He subsequently signed for fellow league team Deportivo de La Coruña, achieving promotion to the top tier in 1991.
In 1997, Aspiazu was appointed manager of his last club Amurrio, still in the third division. He was named in charge of CD Aurrerá de Vitoria in June of the following year, but was relieved from his duties in November.
In 2003, Aspiazu joined Ernesto Valverde's staff at his former club Bilbao Athletic, as an assistant. He remained in the role for the following years, being Valverde's second at Athletic, RCD Espanyol, Olympiakos F.C., Villarreal CF, Valencia CF and FC Barcelona.
- "Aspiazu, la extensión de Arsenio en el campo" [Aspiazu, the extension of Arsenio on the field] (in Spanish). La Voz de Galicia. 19 December 2017. Retrieved 21 May 2018.
- "La reconstrucción de las ruinas griegas" [The reconstruction of the Greek ruins]. Mundo Deportivo (in Spanish). 16 August 2010. Retrieved 26 November 2018.
- "Jon Aspiazu, la mano derecha de Valverde desde hace quince años" [Jon Aspiazu, Valverde's right hand for fifteen years] (in Spanish). Sport. 29 September 2017. Retrieved 21 May 2018.
- "Iker Aspiazu Pérez". Athletic Bilbao. Retrieved 26 November 2018.
- "Capa, con Bustinza, Sabin y Aurtenetxe en el Infantil del 92" [Capa, with Bustinza, Sabin and Aurtenetxe in the 'Infantil' of 92]. El Desmarque (in Spanish). 26 May 2018. Retrieved 26 November 2018.