Selected 107th overall out of Connecticut, Easley led the Huskies last season with 48 catches for 893 yards and eight touchdowns.
A late-bloomer at college, Easley has looked solid so far during spring minicamps and is in contention for a backup spot behind starter Lee Evans.
Signed Wednesday, he becomes the sixth of Buffalo's nine draft picks to sign with the team. The Bills have yet to sign their top three picks, including running back C.J. Spiller, who was selected ninth overall.
To make room on their roster for Easley, the Bills waived linebacker Mike Wright, an undrafted rookie free agent out of Utah.