McGwire replaces Dave Hansen as the Dodgers' seventh hitting coach in eight seasons under Colletti. Hansen was dismissed in October.
"Mark has been able to translate his success as a big league hitter into his work as hitting coach with the Cardinals," Colletti said in a press release. "He earned the respect of both veterans and young players while in St. Louis and the offensive numbers the Cardinals produced under his tutelage speak for themselves. We're excited to have him join our coaching staff and anticipate great things from his work with our hitters in 2013 and beyond."
The 12-time All-Star leaves the same position with the St. Louis Cardinals to take the job in Los Angeles, and the former USC player still owns a home in Orange County. With the Cardinals the past three seasons, McGwire's hitters led the National League by batting .274 with runners in scoring position. Last year, St. Louis led MLB with a .338 on-base percentage.
The hiring of a former first baseman as the hitting coach is a trend for Los Angeles, and it's one that includes current manager Don Mattingly, who served as the Dodgers' hitting coach from 2008 to 2010. Eddie Murray (2006-07) and Jack Clark (2001-03) were also former hitting coaches that were once first basemen.