Dodgers General Manager Ned Colletti said McGwire is coming to Los Angeles after serving as the St. Louis Cardinals' hitting coach for three years.
Under his direction, the 2011 World Champion Cards led the National League in batting average (.273) and runs scored (762). They finished second in both categories last season, when St. Louis again reached the NL Championship Series.
"Mark has been able to translate his success as a big league hitter into his work as hitting coach with the Cardinals," Colletti said. "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."
McGwire -- a 12-time all-star -- became the first player to hit 70 homers in a season in 1998, but his accomplishments were diminished after being linked to banned steroid use.
The 49-year-old turned down a contract extension offer from St. Louis to join the Dodgers.