Joseph Steven Lacob[1] (born January 10, 1956) is an American business executive who was a partner at Kleiner Perkins[2] and is the majority owner of the Golden State Warriors of the National Basketball Association (NBA) and the Golden State Valkyries of the Women's National Basketball Association (WNBA).

[5] Before he joined Kleiner Perkins, Lacob held executive positions with Cetus Corporation (now Chiron), FHP International (a health maintenance organization) and the management-consulting firm of Booz, Allen & Hamilton.

[5] In January 2006, he became part-owner of the Boston Celtics, where he became a co-investor with H. Irving Grousbeck, an entrepreneur and a professor at the Stanford Graduate School of Business.

[10] On July 15, 2010, Lacob and the group of investors he headed agreed to buy the Golden State Warriors of the NBA from Chris Cohan for $450 million, requiring him to sell his minority interest in the Celtics.

[11] The Lacob - Peter Guber group won out over a dozen other bidders for the Warriors, including Oracle chief executive officer Larry Ellison, 24-Hour Fitness founder Mark Mastrov and Texas billionaire financier David Bonderman.