Kelly, 36, joined the Titans as the team's passing game coordinator prior to this past season. He will assume the position previously held by Todd Downing, who was fired on Jan. 9.
Kelly previously spent eight seasons with the Houston Texans, serving in many roles before being named as the team's offensive coordinator (2019-21).
With the Titans, Kelly inherits an offense that finished 28th in scoring (17.5 points per game) and 30th in total yards (296.8 yards per game) this past season.
Also on Tuesday, the Titans hired Charles London as the team's passing game coordinator/quarterbacks coach, Chris Harris as the defensive pass game coordinator and cornerbacks coach and Lori Locust and Justin Hamilton as defensive quality control.