The Falcons (5-3) also had touchdown runs of 58 and 32 yards by Michael Turner, who accumulated 166 yards rushing.
Ryan, who was 17-of-34 for 135 yards, hit Tony Gonzalez on a 2-yard play to open the scoring and Hill's TD came 7 minutes later.
Atlanta had a 24-3 advantage at the half.
Washington's Jason Campbell threw a 3-yard touchdown pass, was picked off by Hill and sacked five times.
Ladell Betts ran 1 yard for another score for the Redskins (2-6).