Diego Castillo was hired as an assistant tennis coach at Pepperdine in August 2025.
Castillo comes to Malibu after serving as an assistant coach at Boise State, where he helped lead the Broncos to a 2025 Mountain West Conference regular-season championship and the program’s third-consecutive NCAA Tournament appearance. With Castillo on staff, Boise State went 21-6 — including an upset over No. 22 Michigan State — and three wins against Power-4 competition. Boise State rose to No. 29 in the Intercollegiate Tennis Association polls, which was the best mark in program history.
Individually, Castillo helped coach three All-Mountain West selections, including fifth-year senior Jett Middleton, who finished at No. 102 in the final ITA national singles rankings.
No stranger to Southern California, Castillo played at UC Santa Barbara for three seasons, helping the Gauchos win two Big West regular-season titles and the 2023 Big West Tournament title. He began his collegiate career at Fresno State, where he played for one season before the program was cut.
Outside of collegiate tennis, Castillo worked as a tennis professional at Millbrook Golf and Tennis Club, located in Millbrook, N.Y. He was also a practice player for professional players at the BNP Paribas Open.
Castillo graduated from UCSB in 2024 with his bachelor’s degree in sociology.
