Heimerdinger, who ran the offense for the Titans from 2000 to 2004, rejoined the team after a stint as assistant head coach and quarterbacks coach for the Broncos.
"Mike was at the top of my list and we are fortunate he was available to come back," Tennessee Coach Jeff Fisher said. "We know each other very well and he is without a doubt the right person to help the offense take the next step."
Heimerdinger replaces Norm Chow, who was fired this week.
The Titans were eliminated by San Diego in the first-round of the NFL playoffs, finishing with a 10-7 record.