(July 20, 1920 – May 14, 1995) was an American football coach.
He was the head coach at Oregon State University from 1955 to 1964 and the University of California, Los Angeles (UCLA) from 1965 to 1970, compiling a career college football record of 104–55–5 (.649).
Prothro moved to the professional ranks of the National Football League (NFL) in 1971 as head coach of the Los Angeles Rams, a position he held for two seasons.
He then coached the San Diego Chargers from 1974 to 1978, tallying a career NFL mark of 35–51–2 (.409).
Prothro was inducted into the College Football Hall of Fame as a coach in 1991.