The 22-year-old, who came through the youth system at Madras RFC, has enjoyed a sustained run of appearances in Glasgow colours so far in 2024/25, featuring in all bar one of the club's 13 matches across all competitions in the campaign to date.
A former Scotland U20 captain, Samuel first joined the senior academy at Scotstoun ahead of the 2020/21 season, before signing a first-ever professional contract with Glasgow Warriors in the summer of 2022.
Having impressed in the FOSROC Super Series for Ayrshire Bulls, he made his Glasgow Warriors debut in November 2022, starting in the second-row in a 37-0 victory over Benetton at Scotstoun.
His first full 80-minute shift came earlier this season, as he helped his side to a narrow 17-15 win over the Scarlets in front of the Warrior Nation - one of 26 appearances for the club to date.
Samuel's form in a Glasgow jersey saw him selected in a senior Scotland squad for the first time ahead of The Famous Grouse Nations Series in 2024, before making his senior international debut against Portugal at Scottish Gas Murrayfield last November.
"I'm really pleased to re-sign with the club," Samuel told glasgowwarriors.org.
"I was a supporter of the club long before I had the privilege to pull on the playing shirt, and I'm buzzing to be able to spend at least another couple of years here.
"Growing up, coming to Scotstoun as a supporter was awesome, so it's still a bit of a pinch-myself moment every time I have the opportunity to run out in front of the Warrior Nation. Even just signing as part of the academy for the first time was a massive moment for me - being able to come in and learn from the guys that I'd grown up watching was a huge deal.
"I just want to keep putting my hand up for more game time and more opportunities to play. I'd love another chance to win something as part of this club - I was part of the squad last season but didn't play in any of the playoff games, so that's a big target for me.
"Making my Scotland debut was a really proud moment as well, so I'm keen to keep performing as best as I can for Glasgow, and hopefully get back into that Scotland setup as well."
Head Coach Smith added: "We're pleased to have retained Alex for the next couple of seasons, as he continues to go from strength to strength.
"He is a player whose development excites us, and he is someone who has great potential for both club and country.
"He's also keen to learn from both coaches and team-mates at every opportunity, and we look forward to continuing to see him develop at Scotstoun."