Warriors fly-half Dan Parks was last week voted players' player of the World Cup.
But Rory - whose brother, Sean, won the Famous Grouse award last season - topped the poll of journalists during Scotland's seven games this season.
Rory said: "I'm delighted and I suppose you could say it's nice to keep the silverware in the family."
Rory pipped Dan and another of his former Glasgow team-mates, centre Andrew Henderson, for the honour.
Rory scored four tries during Scotland's seven internationals and followed that up by scoring on his Sale debut at the weekend.
Sponsorship manager Tara Kildare said: "The Famous Grouse is proud to reward such an exciting and talented player as Rory.
"He is a deserving and popular winner who typifies the spirit of Scottish rugby."
Rory had been runner-up in the players' poll, with Stade Francais number eight Simon Taylor in third.