The highly rated centre joined up with the Warriors from Clermont Auvergne in November, having originally moved to the Top 14 side from Glasgow in 2011.
Since returning as a professional he has made three appearances in the RaboDirect PRO12, scoring a maiden try against the Dragons in the Warriors record 60-3 victory at Rodney Parade earlier this month.
Mark Bennett said: "I have really enjoyed the last few months in Glasgow and I am very happy to have been able to make this move permanent.
"I learnt a lot over in Clermont but this is an excellent opportunity to continue my development in Glasgow and to be involved at an exciting time for the club."
Glasgow Warriors head coach, Gregor Townsend said: "Mark has shown a great deal of maturity since arriving back in Glasgow and we're really pleased that he's signed up for next season.
"Since breaking into the team he has not only shown his attacking threat, but also his defensive qualities. He had to be patient before earning his first start and he did that by impressing at training and working hard on his game."
"When he did get his chance he seized on it, and that's a valuable quality to have."
Guinness PRO12
Suite 208, Alexandra House,
The Sweepstakes
Ballsbridge, Dublin 4, Ireland