The 26 year-old was one of the stars of last season, but his 18-goal haul in his maiden top-flight season was not enough to help the west Londoners retain their English Premier League status.
Austin had been widely expected to leave Loftus Road over the summer but remained after QPR stood firm on their $30 million valuation of the forward, whose contract expired at the end of the season.
However, the Hoops this week accepted what Press Association Sport understands to be a $8.3 million deal for the striker, which was announced by the south coast club on Saturday.
