Newhouse joins the Bengals following a four-year stint with the Green Bay Packers, appearing in all but one game in the past three seasons despite being a backup.
The 25-year-old also played in all four of the Packers' playoff matches during his time with the team, and Bengals offensive line coach Paul Alexander believes that his experience and versatility will benefit the team.
"Marshall has played a lot of football for Green Bay. He'll be a quality addition to our line. He's played left tackle and right tackle and has experience in big games," Alexander is quoted as saying by ESPN.
Newhouse will likely replace former backup tackle Anthony Collins in Cincinnati after he joined the Tampa Bay Buccaneers in the first week of free agency.