The England Under-21 international has been granted a short-term move after failing to command a first-team spot this season, and can feature for the Owls against Derby on Saturday
The England Under-21 international has struggled for first-team appearances, starting just one Premier League game and failing to net a single goal, this season.
The deadline-day signing of Swansea City striker Danny Graham has seen Wickham drop down the pecking order, and boss Martin O'Neill has now sanctioned a temporary switch for the player.
Wednesday are currently struggling the Championship, lying 18th in the table, and will hope Wickham can replicate the same level of performances he previously showed in the division with Ipswich Town that saw Sunderland part with £8.1m for the player in 2011.
The striker has been registered for the Owls in time to feature in the home game against Derby County on Saturday.