O’Keefe, born in Huron, South Dakota, and raised in Los Angeles, attended Santa Maria Junior College and then transferred to Hancock College in 1954.  

O’Keefe eventually graduated from Hancock in ’56 and attended San Jose State for a year before he was drafted into the U.S. Army, where he spent two years in service. He returned to Santa Maria in 1959 and started his professional golf career a year later, joining the PGA Tour in 1961. O’Keefe played on the Tour through 1964.

O’Keefe won the ’63 California State Open and also played in major senior tour championships. He played in the PGA Senior Championship four times and the U.S. Senior Open three times. He played in the British Senior Open at Turnberry in 1989 and ’90, at Royal Lytham & St. Anne’s in 1991 and at Royal Portrush in 1995 and ’98. In 1970, he became a principal owner of Rancho Maria Golf Club.