Rudi Johnson rushed 24 times for 117 yards and two touchdowns for the Bengals (11-3), who capitalized on four turnovers in the first half to lock up the AFC North title. Cincinnati, which held a 24-7 halftime lead, got its fourth straight victory.
Palmer's 30 touchdown passes in 2005 topped the old Bengals' mark of 29 set by Ken Anderson in 1981, the season the Bengals lost to the San Francisco 49ers in the Super Bowl.
Chad Johnson caught 11 passes for 99 yards and a TD for Cincinnati.
Bengals cornerback Deltha O'Neal recorded his 10th interception of the season, surpassing the nine picks by Ken Riley in 1976.
Jeff Garcia completed 13-of-21 passes for a touchdown and was picked off three times for the Lions (4-10), who lost their fifth straight game.