Crowley, who played 19 games for the club in 2011, has secured a one-year extension taking him through to the end of season 2012.
Walters, who has played 14 games for Fremantle since making his debut in round 11, 2009, also agreed to a one-year contract extension that will take him through to the end of the 2012 season.
Fremantle has now contracted all of its senior listed players for 2012 and beyond.
