Sean O'Hair was born on July 11th, 1982 in Texas, USA. He turned pro in 1999 after his junior year at high school.He made five trips to the Qualifying School but had no success. He then played on the Nationwide Tour but only made four cuts out of eighteen starts.

In 2004 he returned to Q-School and got through all three stages to earn his PGA Tour card. On his first season he won the John Deere Classic, earnt nearly $2.5 million and won the Rookie of the Year award. He has had a difficult relationship with his father which is well publicized.