Bryant, 31, worked out for the Bills on Monday. The 323-pound run-stopper's presence will aid Buffalo's defensive line, in part because Marcell Dareus is under NFL suspension for the regular-season opener against Indianapolis.
The Jacksonville Jaguars signed Bryant to a four-year, $19 million contract before the 2014 season, then released him in March before a $500,000 roster bonus was due.
One NFL general manager recently told ESPN NFL Insider Adam Caplan that he saw Bryant as a part-time player and would only use him for 20 to 25 plays per game.
Bryant, who spent his first six seasons with the Seattle Seahawks, started all 16 games last season for Jacksonville, recording 23 tackles, one sack and one forced fumble.