Collins, who turned 33 today and is a former All Black A and New Zealand Barbarians prop, moved to London Irish from the New Zealand club Waikato Chiefs in July 2005, a side for which he made a then record 81 appearances.
The announcement comes on the back of Glasgow's four straight wins in the Magners League, with victories over Leinster at Hughenden, Connacht in Galway, Ulster at Ravenhill and most recently over the Ospreys at home last Friday.
On the prospect of joining the Warriors Collins said: "Glasgow are playing good rugby at the moment and getting big results so I'm keen to help them move even further forward. I've heard great things about the Magners League too so I'm looking forward to playing in that.
"Their results have been excellent. I've played against Ulster at Ravenhill a few times and I know how difficult it is to go there and win and the Ospreys are a great side so it shows how well the Warriors are doing just now. It's exciting to be joining a team capable of taking scalps like that," he added.
Warriors coach Sean Lineen said: "This is a fantastic acquisition for Glasgow because Michael is a well respected player and natural leader. We have a crop of young props here, like Moray Low, who will learn a huge amount from someone of Michael’s experience.
"I have no doubt that he will bring a lot to our plate having seen him play. He’s a mobile and aggressive player and the fact that he is comfortable on either side of the scrum is a bonus for us," he added.