Born in Monroe, Iowa, O'Connor spent much of his early life playing golf, as his parents managed a country club.

O'Connor attended and played basketball at Newton High School and Drake University; he became team captain in his senior year of college despite his slight frame and bad eyesight.

[3] He became the official coach in the 1951–52 season, in which the team achieved a 19–3 record and a second-place finish in the Big Ten Conference.

In the 1955–56 season, which was the Fabulous Five's final season together, the Hawkeyes won 17 consecutive games and advanced to their only National Collegiate Athletic Association (NCAA) championship game in school history,[5] where they lost to the University of San Francisco, marking the end of Iowa's most successful era of basketball.

[1][4] O'Connor coached the Hawkeyes for the next two seasons, compiling a combined record of 21–23 before dying in a highway accident on April 22, 1958, at the age of 44.