The 23-year-old scrum-half made a strong impact off the bench in Saturday's 25-21 win over the Vodacom Bulls in the Investec Champions Cup last 16, helping Glasgow secure their first-ever home quarter-final in the competition.
A former Scotland U20 captain, Afshar has made 35 appearances for the club since debuting in November 2023, when he came off the bench in a 33-20 victory over Ulster at Scotstoun. His first try followed in February 2024, marking his first start with a bonus-point score in a 40-7 win over the Dragons.
Afshar previously progressed through the club's senior academy and has worked with familiar faces along the way, including future teammate Jamie Dobie at Merchiston Castle and Sean Kennedy at Stirling Wolves.
At representative level, he featured for Scotland A in a 24-24 draw with Italy XV in Rieti this February, having also played in their 2024 win over Chile in Edinburgh.
"I'm really happy to extend my stay at the club," the scrum-half told glasgowwarriors.org.
"It's been a really good few years and I'm enjoying being part of the setup. The brand of rugby we play and the success we've seen over the last couple of years has been great and it's a really exciting time to be a part of this club.
"There's so much squad rotation that it really helps you build relationships with those around you, and it helps everyone build so much experience too. There's also a big emphasis on improving as a person, too - it's not all about how you are on the field, but Franco always says good people make good players. Being able to learn from the older boys here is brilliant.
"I've had a couple of run-outs on the wing this year, and being able to be multi-positional is a huge asset - it's a string I'm always happy to add to my bow. We run the six-two split on the bench here, and you look at the success [Jamie] Dobie has had covering both scrum-half on the wing - I'm not saying I'm anywhere near his level yet, but having that versatility and understanding is only a good thing.
"The environment is so good here at the moment. The work everyone is putting in is translating to the performances we're putting out on the field, and there are so many talented young guys coming through. We're always challenged to be the best version of ourselves, and that's what I'm striving towards."
Head Coach Franco Smith added: "Ben continues to grow and develop as a player, and we are pleased that he will be continuing his progression at Scotstoun for the next couple of seasons.
"He works hard to improve all areas of his game, and is keen to learn from those around him at every opportunity.
"He is also dedicated to becoming the best version of himself off the field, and has fully bought into what we are building here at Scotstoun."