Palmer was 23-of-32 passing with one interception. Chad Johnson caught four of Palmer's passes for 131 yards and a pair of scores.
T.J. Houshmandzadeh hauled in nine passes for 90 yards, tying New England's Wes Welker for the league lead with 112 receptions this season. Kenny Watson also scored on a two-yard run for the Bengals (7-9), who wrapped up the season with their first two-game winning streak.
The Dolphins (1-15), became the eighth team to complete a 1-15 season since the schedule expanded in 1978.