The university announced Wren Baker's resignation, effective Feb. 22, on Wednesday morning.
Baker has served as the university's director of athletics since February 2011.
Baker accepted a position as the deputy athletic director of external affairs at the University of Memphis. He will begin his duties in March.
Northwest President Dr. John Jasinski said the university will conduct a national search to fill the open position. Lori Hopkins will serve as Northwest's interim athletics director.