The 1978 Cal State Fullerton Titans football team represented California State University, Fullerton as a member of the Pacific Coast Athletic Association (PCAA) during the 1978 NCAA Division I-A football season. Led by fourth-year head coach Jim Colletto, Cal State Fullerton compiled an overall record 5–7 with a mark of 2–2 in conference play, placing fourth in the PCAA. The Titans played home games at Falcon Stadium on the campus of Cerritos College in Norwalk, California.