Munchak was fired by the Titans at the beginning of the month, with his failure to make changes to his coaching staff being cited as a key reason.
After leaving Tennessee, he interviewed for head coaching positions with both the Detroit Lions and Cleveland Browns, as well as an offensive coordinator role with the Houston Texans.
On Wednesday, CBS Sports insider Jason La Canfora said via his personal Twitter account: "Titans former HC Mike Munchak going to the Steelers as OL coach. Deal being finalized tonight."
The Steelers are yet to officially confirm Munchak's appointment.