Ryan completed 25-of-32 pass attempts for 279 yards, hooking up with Roddy White eight times for 153 yards and two scores as the NFC South champion Falcons (13-2) logged their fifth win in six games.
Julio Jones made seven grabs for 71 yards and a score, while Michael Turner ran the ball 13 times for 41 yards in the victory, in which Atlanta took advantage of three Detroit turnovers.
Matthew Stafford went 37-of-56 for 443 passing yards and an interception for the skidding Lions (4-11), who dropped their seventh straight.
The Lions wide receiver made 11 catches for 225 yards, giving him 1,871 for the season. He will attempt to become the first receiver ever to gain 2,000 receiving yards in the Lions' final game next week against Chicago.