Fagerson brought up 150 appearances in a Glasgow jersey in the opening match of the 2024/25 campaign away to Ulster and has pledged his future to the club, as preparations intensify for the meeting with Edinburgh at Hampden Park this Sunday.
Speaking ahead of the 1872 Cup opener, Fagerson said: "Weighing up all the options, it was clear very quickly that Glasgow was definitely the standout choice for both for myself and my family.
"I love being part of this group and coming to work with my mates every day. We're all trying to drive each other forward and make each other better on and off the field. That's definitely the mantra of this squad, and this is the best place for me to continue my rugby journey.
"We're a family-driven club, so making sure my wife and my kids were happy was huge for me. They feel just as much a part of this club as I do, so to be sticking around and being part of that environment is really exciting and an opportunity for which I'm truly grateful.
"Once you get that winning feeling, you just want to experience more of it. To have that experience last year with the playoff run and winning the league down in Pretoria alongside some of my best mates and my little brother - it was a dream come true.
"That in turn has really driven how we train this year - we want to go out and win that trophy once more, and be the best version of ourselves both in the league and in Europe. That mindset is only going to serve us well as we move forward and I'm excited to be a part of it."
Head Coach Smith added: "Zander is a world-class operator in the front-row, and we are extremely pleased to retain a player of his calibre for the coming seasons.
"He is one of the top tight-heads in world rugby, with his quality at the set-piece and dynamism with ball in hand clear for everyone to see.
"Moreover, he is a true family man and a person who embodies what it means to be a Warrior, and we look forward to continuing to work closely with him as we progress on the Glasgow Warriors journey."