Andy has signed with the Tykes until the end of the season. He's joined in the Leeds 22 by two other former Glasgow players - Gordon Bulloch and Mark McMillan.
Leeds director of rugby Phil Davies admitted he was shocked and delighted at securing Andy's services on a short-term contract to the end of the season as a replacement for injured Rob Vickerman.
He said: "We're a bit short in the back line and I'm amazed he became available.
"He will bring us experience and stability to the middle of the field.
"Andy has only had a couple of days' training but he's a strong ball-carrier and defensively pretty strong as well."
Bristol include former Glasgow favourites, Tommy Hayes and David Hilton.