Reggie Aaron Christiansen (born August 28, 1975) is an American college baseball coach who has served as head coach of the Sacramento State Hornets baseball team since 2011. Christiansen was previously head coach at Menlo and South Dakota State. At Sacramento State, Christiansen has over 360 wins, with two Western Athletic Conference Coach of the Year honors in 2012 and 2014 and three appearances in the NCAA Tournament in 2014, 2017, and 2019.