The 21-year-old joins on loan for the remainder of the 2013-14 season, with Rovers having the option to purchase.
Marseille-born, Dabo has come through the youth ranks at Montpellier, making his debut as an 18-year-old against Paris Saint Germain in May 2010.
In total, the box-to-box midfielder has made 19 appearances for the French club before securing his move to England.
"I'm very glad to be here because I am coming to a good team," Dabo told Rovers Player
"I'm here to enjoy my football and to play well with the team and maybe catch the play-offs.
"It is a new experience for me - a new country. I'll try to speak English, have a good attitude, keep smiling and enjoy my time here, then everything will be okay."
Dabo will not be in the squad for tonight's game at Barnsley, as Rovers await international clearance for the Frenchman.
subscribers will be able to watch our exclusive interview with Bryan Dabo later this evening.
• Meanwhile, Raheem Hanley has today mutually agreed to the cancellation of his contract.