He is one of seven players to have committed to the Warriors after Firhill favourites Justin Va'a, Kevin Tkachuk and Moray Low agreed to deals while Mark McMillan sealed a return from Wasps.
Finally, Ruaridh Jackson from Glasgow Hawks joined Forrester and John Welsh, both from GHA, in securing terms with the Warriors for next season.
"I've been involved with Glasgow for quite a while now because I used to be an apprentice at the club," said Forrester.
"It's been an ambition of mine to become a full-time professional with Glasgow and I'm delighted I get the opportunity this year.
"Pre-season has been going really well, the fitness team seem to enjoy watching us in pain because they're working us really hard.
"It was a kind of blessing in disguise that I started my training early along with a couple of the more experienced guys like Sam Pinder and Hefin O'Hare as well as having another new face, Jon Welsh, there as well. It's made settling into the professional routine much easier.
"It's been a great experience so far but I just want to get into the thick of it now and play some rugby in front of the Glasgow supporters who were phenomenal last season."