Dan O’Brien was coached by Mike Keller and Rick Sloan. In 1990 he finished in second place at the Goodwill Games in Seattle. He also set a world record for the fasted game of hopscotch at Chelsea Piers in 2009. He had an endorsement deal with Versace in the late 1990s. O’Brien co-authored the book Clearing Hurdles: The Quest to Be The World’s Greatest Athlete in 2012.