McBeth has represented both Scotland and South Africa at U20 level.
He's played for the Lions in Super Rugby and the Golden Lions in the Currie Cup.
The loose-head made 10 appearances for the Johannesburg-based franchise, his professional debut having come in a 47-39 victory over the Jaguares in March 2019.
McBeth's move sees the prop re-unite with former Scotland U20 team-mates Ross Thompson and Murphy Walker, having made four appearances in the 2018 U20 Six Nations and touched down for a try against Ireland.
He has also earned U20 honours for South Africa, starting in three matches at the 2018 U20 World Championship in France.
Away from rugby, the loose-head is a keen fisherman and cites Springbok legend Os du Randt as his childhood rugby idol.
Speaking following the announcement, McBeth told glasgowwarriors.org: "I'm very thankful for the opportunity to join the Warriors.
"It will be an honour to represent them for the next few years. I can't wait to meet the team and start to train with them.
"It's a dream come true for me. Glasgow has always stood out for me because of the exciting brand of rugby that they play and I'm very excited to become a part of that."
Glasgow Warriors Head Coach Danny Wilson welcomed McBeth's signing, adding: "Nathan is a player we've had our eye on for some time.
"He's a physical ball-carrier and a young man who is willing to learn and improve his own game.
"To be able to add a young, Scottish-qualified prop of his calibre is a real boost and we're looking forward to seeing what he can do."