The loose-head prop will link up with his new team-mates for block one of pre-season at Scotstoun next week, with the formal announcement following his signing of a contract earlier in 2022.
Capped 34 times by Scotland to date, the 30-year-old makes the switch to Glasgow following three seasons at London Irish, making 40 appearances in total for the English Premiership outfit.
Prior to his move south, Dell represented Edinburgh with distinction over five seasons, having initially made the move to the capital in 2014.
His form during the 2016/17 season for both club and country saw him called into the British and Irish Lions squad as injury cover on the 2017 tour of New Zealand, becoming the 834th player to pull on the famous red jersey when coming off the bench against the Hurricanes in the final midweek match of the tour.
Dell has also represented the Barbarians, representing the invitational side in last month's 26-7 win over Spain in Gijon.
Further recruitment will be overseen by the club's new Head Coach, with the process to fill the vacancy ongoing ahead of the 2022/23 season.
"I'm excited to get stuck into life in Glasgow," Dell told glasgowwarriors.org.
"It's a good group of boys here, and it's always been a club that's played an attractive brand of rugby. To come back to Scotland and be a part of that is a really exciting prospect.
"My gran is originally from Paisley, too, so there's a really nice family feel to coming back north and pulling on the Glasgow shirt.
"There's a really good crop of guys in the front-row here, too - Jamie [Bhatti], Oli [Kebble] Simon [Berghan] and Zander [Fagerson] I obviously know from Scotland camp, but even guys like Nathan McBeth and Murphy Walker are really talented young props. The good thing is that we'll all push each other and challenge each other to get better, which can only be good for the club overall.
"It'll be nice to have the fans on my side, too! The crowd always gets stuck into you as the opposition and always get right behind their team, it's a brilliant atmosphere. I can't wait to be a part of it and get this club back to where it should be."
Glasgow Warriors Scrum Coach Al Dickinson added: "We're excited to add Allan to our squad ahead of the new season.
"He's a loose-head who has proven he can perform at the highest level, and adds to the quality and depth of the props we already have at Scotstoun.
"He's also gained valuable experience in the English Premiership, which I know from experience to be a relentless league for front-rowers and will only have made him a better player.
"His enthusiasm for the game and experience will drive and challenge the players around him, and we're looking forward to welcoming him to the environment for pre-season next week."