Cummings made his professional debut in the opening match of the 2015/16 campaign, starting in the second-row against the Scarlets at Scotstoun before scoring his first try in Glasgow colours a week later in victory over Connacht.
The former Glasgow Hawk and Kelvinside Academy product earned his first professional contract in the summer of 2016 and has since gone from strength to strength, becoming an integral figure in the engine room for both club and country.
He earned his 100th appearance for his boyhood club in April 2023, leading the team out before the record-breaking 73-33 win over the Dragons in the EPCR Challenge Cup at Scotstoun.
Cummings' form in the 2018/19 campaign saw Scotland Head Coach Gregor Townsend hand the second-rower a senior Scotland debut away to France in a 2019 Rugby World Cup warm-up match, with Cummings having previously captained his country at U20 level.
To date, he has won 33 caps in the dark blue jersey, appearing at both the 2019 and 2023 Rugby World Cups and appearing in all eight matches for Scotland across the two tournaments.
"Representing this club means a lot to me," Cummings told glasgowwarriors.org.
"It's the club I've been a supporter of ever since I was a boy, so every chance I get to represent this team is special.
"It's a great group to be a part of right now. We've got a great group of guys that train hard together and work towards putting good performances out on the weekend. There's huge competition for places within the squad and a number of great young players breaking into the team now as well, which is pushing us all on to represent the team the best we can.
"Our ambition as a club is to win silverware. Getting to experience the [Guinness PRO14] final at Celtic Park in 2019 and then the [Challenge Cup] final in Dublin last year confirmed that those are the games that we want to be involved in, the big matches at the end of each season. We want to push on, take that next step and give everything for this club."
Head Coach Franco Smith added: "To be a great team we must first have a great squad, and we are extremely pleased to retain a second-rower of Scott's calibre for at least the next couple of seasons.
"He has developed into a real leader within our squad, both through his work around our set-piece and his performances on the field, and he is someone who is highly passionate about representing his hometown club.
"We firmly believe that there is still more to come from Scott, and we look forward to continuing to work closely with him over the coming years."