Thomas, 30, has 36 catches for 402 yards and three touchdowns this season. He had three catches for 30 yards in the Broncos' 30-23 loss to the Kansas City Chiefs in Week 8.
The Texans made the move after losing wide receiver Will Fuller for the season to a torn ACL. Fuller -- the No. 21 overall pick in the 2016 NFL Draft -- had 32 catches for 503 yards and four touchdowns before the knee injury.
Houston faces Denver at 4:05 p.m. on Sunday in Denver.