Celine Dion -- Sued for Screwing Employees Out of Overtime

Celine Dion and her husband are a couple o' tight wads when it comes to compensating employees at their massive Florida compound ... according to a new federal lawsuit filed by their ex-handyman.

TMZ obtained a copy of the suit filed by Keith Sturtevant Wednesday -- and in it he claims he was hired in March 2009 as a "warehouse manager" ... but says he also regularly worked at Celine and Rene Angelil's giant home in Hobe Sound, Florida.

According to the suit, Sturtevant fixed ice makers, cleaned house shutters, built stages, and ran miscellaneous errands for Celine and Rene -- and although he had a "manager" title ... Sturtevant claims he "did not have the power to hire or fire employees."

The suit alleges Celine and Rene "improperly and illegally designated [Sturtevant] as an exempt employee" -- allowing them to avoid paying the overtime ... which Sturtevant claims he's owed since he regularly worked more than 40 hours per week.

Sturtevant's suit claims Celine and Rene improperly slapped the "exempt employee" label on several other employees too. He's suing for all his back overtime wages.

We've reached out to Celine's reps for comment, but so far ... no reply.