The scrum-half has been with the Pro12 side for over six years and became co-captain this past summer.
Born in Dorset, he made several appearances for the Scottish under-20s side before becoming a full international in 2012, earning 18 caps.
He’ll now remain with Glasgow beyond the end of this season when current head coach Gregor Townsend steps aside to become Scotland boss, with Dave Rennie taking over.
Pyrgos said: “I’m really happy to sign for another two years, it was an easy decision. I love everything about Glasgow Warriors and the club means a huge amount to me.
“I’ve had a brief chat with Dave Rennie and he told me about his vision for the club and his rugby philosophy, and it’s exciting.
“I’m excited for the future here and we’ll be working extremely hard to continue to compete for trophies every season. I believe we have a squad capable of doing that and that’s the main reason I wanted to stay.”