William Edward O'Brien (March 11, 1923 – December 1, 2000) was an American football coach and official. He was the seventh head football coach at the Southern Illinois University Carbondale, serving for three seasons, from 1952 to 1954, and compiling a record of 6–20. O'Brien was an official in the National Football League (NFL) for 18 seasons, from 1967 through 1983, officiating in Super Bowl X in 1976. He wore number 83 for the major part of his NFL career. He was also a professor at Southern Illinois University.