The winger, who can play on both the left and right wing, has penned a contract at S6 which will keep him the club until December.
Erstwhile Liverpool star Partridge joins Manchester United loan star Chris Eagles and American defender Frankie Simek at Wednesday this week as the Owls boss gears up for the start of the championship season.
Other new faces at the club include former Ipswich defender Drissia Diallo, ex Plymouth stopper Graham Coughlan and midfield playmaker Burton O'Brien who was signed on a free from Livingstone.