Stallings confirmed that he informed his players that he is taking the Pitt job.
Sources said is a six-year deal.
Stallings, 55, had been the head coach at Vandy for 17 seasons and made the NCAA tournament seven times.
The Commodores were expected to battle for the SEC title this season with a roster that included Wade Baldwin and Damion Jones. However, Vanderbilt finished 19-13 overall and in a three-way tie for third place in the SEC. The Commodores made the NCAA tourney and lost to Wichita State in the First Four.
There was speculation that Vanderbilt was expected to sever ties with Stallings, but he was able to get another job before a decision was made about his future with the help of Todd Turner — the former Vandy athletic director who hired him. Turner now runs a search firm called Collegiate Sports Associates that has been retained by Pittsburgh to help with the search.
Panthers athletic director Scott Barnes had reached out to several other candidates but was spurned, one source told ESPN.
Barnes came from Utah State less than a year ago and will hire Stallings to replace Dixon, who left last week to return to his alma mater, TCU.