The Cowboys signed Valdes-Scantling to a one-year contract Monday, Tom Pelissero of NFL Network reports.
Valdes-Scantling appeared in 10 regular-season games with the 49ers and Steelers last season, compiling 14 catches for 120 yards and one touchdown. The 31-year-old is joining his fifth team in the last two calendar years and will attempt to win a job with Dallas this summer. He'll compete with Ryan Flournoy, KaVontae Turpin, Jonathan Mingo and others behind CeeDee Lamb and George Pickens.