Financial terms of the contract were not yet available. Royals was recently released by the Bills.
In Cleveland, Royal becomes the sixth tight end on the roster, but should battle veteran Steve Heiden for the starting job. The Browns recently traded starter Kellen Winslow to Tampa Bay. Other tight ends on the roster include Brad Cieslak, Darnell Dinkins, John Madsen, and Martin Rucker.
Royal, 30, is coming off his best season in the NFL. He started in seven of 15 games for Buffalo last year, and caught 33 passes for 351 yards and one touchdown. All those numbers are career highs.
The former LSU star, who first came into the league as a fifth-round choice of Washington in 2002, is an effective blocker.
He played his first four seasons with the Redskins, and joined the Bills in 2006.
Len Pasquarelli is a senior NFL writer for ESPN.com.