After playing his club rugby with Cambuslang and Glasgow Hawks, Weir spent six years with the Warriors before moving to Edinburgh for two campaigns, and ending up with Worcester Warriors for three seasons.
Speaking in The Herald, Weir said: "I am a Glasgow boy and having a young family back in Glasgow was a huge driving factor, as was the opportunity to play for the Warriors again, because it is a club I am hugely passionate about and supported as a young boy.
"It has fallen into place perfectly for personal reasons and there is a lot a change happening at the club, so it is great to be back to play a part in that."
Danny Wilson sees Weir's experience as a valuable resource in the development of Glasgow's young stand-off Ross Thompson. Thompson grabbed his opportunity last season with a run of impressive performances and Warriors have also signed Argentina international Domingo Miotti from Super Rugby so competition for the number ten jersey could be intense. While willing to play the mentor role Weir fully intends being in the mix for a starting spot.
"I am going into my 12th season in professional rugby and have a bit of experience behind me so if I can help Ross in any way then I am willing to do that," said Weir. "But my best rugby is round the corner and I have to concentrate on taking every opportunity that comes my way because every time I take the field it is chance to play. I am really excited about helping push the club forward in any direction I can.
"Experiencing the Premiership has helped me as a rugby player. The quality I was playing with and against each week was great. It's a slightly different profile in terms of broadcast and going to those historic venues to play the big English clubs. I'll take those experiences from down south and dealing with the pressures of relegation, and it will help me enjoy a Glasgow brand of rugby that we seem to be getting back to."