Taggart also announced the hiring of former Washington State assistant head coach Joe Salave'a, who will take on the same duties with the Ducks in addition to coaching the defensive line.
Cristobal spent the past four seasons as an assistant head coach with the Crimson Tide. This past season, he coached tackles and tight ends, and was also Alabama's recruiting coordinator.
Matt Lubick was the Ducks' offensive coordinator in 2016. He left to become receivers coach at Ole Miss after former Oregon head coach Mark Helfrich was fired.
Cristobal was previously head coach for the Florida International Panthers from 2007-12, compiling a 27-47 record. He has also been an assistant at Miami, his alma mater, and Rutgers.
Reaves worked with Taggart the past four seasons at South Florida, where he worked his way up to become associate head coach in 2016.
Salave'a spent the previous five seasons with the Cougars, where his unit ranked 29th in FBS in run defense (134.23 yards per game) last season.