No terms were disclosed, but Simms is the second free agent signed by Denver in two days, and the 12th this off-season after Denver missed the playoffs in 2008 for a third straight time.
In four NFL seasons with Tampa Bay and the Tennessee Titans, the 6-foot-4 inch Simms has completed 292-of-494 (59.1%) passes for 3,094 yards with 12 touchdowns and 17 interceptions.
He has appeared in just one playoff game, in which he completed 25-of-38 (65.8 percent) passes for 198 yards with two interceptions in a start for the Buccaneers in their NFC Wild Card Game against the Washington Redskins during the 2005 season.
Simms was a third-round pick in 2003 by the Buccaneers out of Texas. The Broncos plan to make him a backup to Jay Cutler.
The Broncos inked running back J.J. Arrington Wednesday and have also free agent signed strong safety Brian Dawkins and linebacker Andra Davis.