William DeWitt, Jr., American businessman
William Orville DeWitt Jr. (born August 31, 1941) is an American businessman who is currently the managing partner and chairman of the St. Louis Cardinals, a professional baseball franchise which competes in Major League Baseball (MLB).

The Cardinals have won two World Series – in 2006 and 2011 – during DeWitt's time as owner. In addition to the Cardinals, DeWitt has also owned or invested in the Cincinnati Stingers hockey club, Baltimore Orioles, the Cincinnati Reds and the Texas Rangers. Business interests outside baseball include Reynolds, DeWitt & Co., which owns Arby's franchises and invests in U.S. Playing Card Company, and the petroleum company Spectrum 7.