Campbell, 27, was one of the few remaining players with the Browns since they re-entered the league in 1999. Last season, he started 16 games and had 25 catches for 179 yards and three touchdowns.
He became expendable in Cleveland since the Browns are deep at the tight end position. Darnell Sanders, Aaron Shea and Steve Heiden all should vie for playing time next season.
Campbell should get a chance to play with the Bills, who released Riemersma on Thursday after the tight end refused to take a significant pay cut.
In 46 career games, Campbell has 46 receptions for 390 yards and four touchdowns.
The Browns only have three starters -- quarterback Tim Couch, wide receiver Kevin Johnson and cornerback Daylon McCutcheon -- remaining from their expansion season.