Mark O'Brien was an American sales executive and television show creator.

His career began in the mid-1980s at Telepictures. After they merged with Lorimar Television and Warner Bros. Television Group absorbed Lorimar, O'Brien found himself in the position of being a key player in licensing televisions shows such as Friends, ER, Ellen, Two and a Half Men, The People's Court, and Extra.

In 1999, O'Brien became a senior vice president, overseeing sales for Warner Bros. Domestic Television Distribution's western region.

He would go on to form Mighty Oak Entertainment and sell his first series, Whacked Out Sports, to NBC. That series would expand into a collection of six original television programs including Goofball Sports, Whacked Out Videos, Monster Knockout, and Sportz-A-Palooza.

O'Brien died November 9, 2020, in Newport Beach, California. He was 63.