Juan Castillo (born October 8, 1959) is the offensive line coach for the Baltimore Ravens. He was defensive coordinator for the Philadelphia Eagles of the National Football League from February 2, 2011 to October 16, 2012. He played college football at Texas A&I as a linebacker. He played for the San Antonio Gunslingers of the United States Football League from 1984–1985. He joined the Eagles in 1995 as an offensive assistant. He was promoted to tight ends coach in 1997, and switched to offensive line coach in 1998.
Castillo was hired as a consultant by the Baltimore Ravens. At the time of the hiring, the Ravens were preparing to play in Super Bowl XLVII. Castillo would officially join the coaching staff for the 2013 season as the run-game coordinator and held the job for one season, before serving as the offensive line coach from 2014 to 2016. In 2017, Castillo was hired by the Buffalo Bills to become the offensive line coach and run-game coordinator under new head coach Sean McDermott. Castillo joined the Michigan Wolverines coaching staff as an offensive analyst for the 2019 season. Castillo was hired by the Chicago Bears as offensive line coach on January 5, 2020. He was named tight ends coach of the Washington Commanders on February 21, 2022.