The decision by the Board of Pardons and Paroles came after the state legislature passed a law in the spring permitting posthumous pardons to be granted for convictions at least 75 years old, the Montgomery (Ala.) Advertiser reported.
The three pardoned men, Haywood Patterson, Charlie Weems and Andy Wright, were the last of the men to have convictions on their records.
A group of scholars petitioned the board in October to grant the pardons. Their petition was endorsed by judges and district attorneys in the two counties where the initial trials occurred.
One of the nine men, Clarence Norris, received a pardon in 1976. Charges were ultimately dropped against the five other men.
Patterson, Weems, Wright and Norris were convicted on rape charges in 1937 after three trials, two landmark U.S. Supreme Court decisions and one accuser recanting her accusation.
Patterson died in 1952. Weems and Wright were eventually released. Norris died in 1989.