Hamilton was signed by the Colts on Monday, the team's official site reports.
Hamilton, who dressed for three regular-season games with the Texans in 2017, hit the free agent market in June after being released by the Cardinals. The 27-year-old figures to provide depth at wide receiver throughout the remainder of the preseason while the unit deals with a handful of injuries, including a torn ACL for sixth-round pick Deon Cain.