He has signed a four-year deal to stay at the club and goes straight into the squad for tomorrow's home opener against Reading.
The 6'1'' striker joined Wolves in 2010 and scored 25 goals over two seasons for the club.
Sunderland Manager Martin O'Neill told safc.com:
"It has been no secret that we needed to strengthen our attacking options and Steven has a proven track record of scoring goals. He is young and constantly improving and he will be a very welcome addition to the squad. I'm delighted that we've been able to bring him to Sunderland."