Chelsea Handler is suing a lingerie company ... claiming she was completely blindsided after spending countless hours and tons of her own cash while agreeing on a deal to promote the brand.
According to legal docs, obtained by TMZ, Chelsea cut a deal with a company called ThirdLove to promote its clothing. She claims the company loved Handler's unique body-positive image and brand and thought it was a fit for its customers.
Chelsea says she went through a specialized exercise routine to stay in shape and get ready for the photo shoots ... and claims she passed on other potential deals to honor her exclusive commitment to the company.
She claims she had to fly out to Canada from L.A. for a photo shoot as part of the deal -- and did so on her dime. But, Handler claims ThirdLove ended up pulling the plug on the entire thing at the eleventh hour.
The comedian and late-night host is seeking no less than $1.5M from ThirdLove.
We've reached out to ThirdLove for comment ... so far, no word back.