The 24-year-old, who can play at fly-half, centre and full-back, scored a try as Canada Sevens lost to Scotland in the Commonwealth Games last month having already played against Scotland in a full international in June, one of 12 appearances for his country.
The former Doncaster Knights player, who teams up with fellow Canadian DTH van der Merwe at Scotstoun, said: "Glasgow is a really good club and when Gregor gave me a call, I jumped at the opportunity.
"I've been playing with Canada Sevens recently, but I felt this was a great opportunity and couldn't say no. DTH is one of my best friends and he spoke very highly of the club. I know a lot of the players from the sevens circuit and I played against Scotland in the summer Tests. I'm here for three months and I'll keep my head down and work hard as I'd love to be here longer."
Braid could feature when Gregor Townsend's PRO12 runners-up host Harlequins in a friendly tomorrow.
Townsend said of Braid: "He has a real desire to develop as a professional rugby player and we're delighted to bring him in ahead of the new season."