Fagerson's contract extension sees him continue his journey with the club with whom he made his professional debut, having come off the bench in a 43-20 victory over Benetton in October 2014.
The tight-head enjoyed a breakout campaign in 2015/16, establishing himself in the Glasgow setup and claiming the Land Rover Young Player of the Season prize at the club's annual Awards Dinner.
Since then, the former High School of Dundee pupil has gone from strength to strength in Glasgow colours, including playing a key role in the club's run to the 2019 Guinness PRO14 Final at Celtic Park.
His importance to Glasgow Warriors was further underlined in 2020, with his team-mates voting him as the Denholm Energy Services Players' Player of the Year for the 2019/2020 season.
Fagerson became the fourth youngest prop in his country's history to be capped at senior level when making his debut against England at BT Murrayfield in 2016.
The tight-head wrote his name further into the Scottish rugby history books on the 2018 summer tour, becoming part of the 22nd pair of brothers to play for Scotland in the same Test when lining up alongside younger brother Matt against the USA.
His impressive form for both club and country was recognised by British and Irish Lions Head Coach Warren Gatland, who named him as one of three tight-heads in his 37-man squad for the 2021 tour to South Africa.
Fagerson became the 848th player to pull on the red jersey when he came off the bench against the Sigma Lions, as well as becoming the seventh Warrior in the club's professional history to represent the B&I Lions.
He then registered his first try in Lions colours in the victory over Stormers, coming off the bench to crash over from close-range in a 49-3 win.
Speaking following the announcement of his renewal, Fagerson expressed his enthusiasm at being able to continue his journey with the Warriors.
"I'm very happy to be continuing at Glasgow for the foreseeable future," the prop told glasgowwarriors.org.
"Glasgow is an incredibly special place for my family and I and it's become our home.
"I'm excited to keep developing as a player over the next couple of seasons and to help this team to achieve our potential, both individually and collectively. The signings Glasgow has made, both with coaches and players mean we have a very exciting future ahead of us both on and off the field.
"The culture and environment at Scotstoun is unlike anywhere else, it's a truly special club. I'd also like to thank Scottish Rugby for giving me the opportunity to continue to advance my career from within Scotland, and I'm going to continue to give my all for both club and country every time I'm selected."
"I can't wait to get back out and playing in front of our fans, who create an atmosphere that's right up there with the best in Europe. Hopefully it's not too long before we can get the Warrior Nation back where they belong - in the stands in a sold-out Scotstoun."
Head Coach Danny Wilson was delighted to secure the services of the British and Irish Lion beyond the expiration of his current contract, saying: "It's great news that Zander has signed a new long-term deal with the club.
"It's great to be able to retain someone of Zander's calibre who has already gained international and British and Irish Lions honours, as well as becoming a club centurion all by the age of 25.
"He is a world-class tighthead prop who has really kicked on these last few years. He's an extremely effective scrummager who offers a huge amount in the loose as both an attacker and a defender.
"We're excited about the direction in which this team is heading and Zander will play a big part in the club's future.
"We look forward to continuing to work with him.
Glasgow Warriors Managing Director Al Kellock underlined the significance of Fagerson's re-signing, adding: "It's very important that our players live and grow our club values, and Zander does that and more
"His willingness to do the extras in training and hunger to learn from those around him makes him a perfect role model for any aspiring professionals out there.
"Watching him go from strength to strength has been a privilege and I'm incredibly pleased that Zander has decided to extend his contract with us. We talk a lot about what it means to be a Warrior, and Zander is someone who epitomises all that is good about our club.
"I'd like to thank Scottish Rugby for working with us to extend Zander's contract - it's a real statement of intent to be able to retain the services of a tight-head of his calibre, and someone who is only going to keep getting better for both club and country.
"He's an incredibly important part of our squad both on and off the field and I'm excited to see what he can do in Glasgow colours over the next few years."