The highly rated 26-year-old has signed a two-year contract that will see him move to Sixways Stadium in the summer ahead of the 2010/11 season.
Rooney previously played rugby league for the Penrith Panthers in the National Rugby League and earned representative honours with City Origin, New South Wales and Australia. He made his Penrith debut in 2001 against the Canberra Raiders and was a member of the 2003 Premiership winning team, scoring two tries in the 18-6 win over the Sydney Roosters.
The flying back, who is an English qualified player through his parents, made the cross code switch and relocated to the south of France to play for Toulon in 2008. In his first season he played 16 games in the Top 14 and scored five tries, also playing six games in the European Challenge Cup.
"We're delighted to sign Luke Rooney and he is a big capture for us," said Director of Rugby Mike Ruddock. "He is the nearest type of player I have seen out there who plays the same way as Chris Latham."