Hughes was selected in the first round of the 2010 draft by the Indianapolis Colts, but in his three years at the club, he struggled to make an impact.
The 24-year-old was traded during the off-season to the Bills in exchange for linebacker Kelvin Sheppard.
"Now I'm a Buffalo Bill, and I'm here to show everyone that I can play football at this level," he told reporters.
"I have expectations, the way that I like to play the game — be out there playing fast and relentless, getting after the quarterback, the ball carrier, whoever that may be."
Buffalo begin their pre-season campaign against the Colts next Sunday.