Ryan Seacrest -- No Fabulous Parting Gift For Julianne Hough

A story is circulating that Ryan Seacrest pulled a Simon Cowell by buying a $3 million mansion for his ex-GF Julianne Hough ... but TMZ has learned -- absolutely, positively false.

As the story goes -- Julianne sold her Nashville condo and is moving into the digs Ryan bought. But sources who know the situation tell TMZ ... he has not bought her anything as a parting gift -- nada.

But Ryan did buy her something before the breakup ... we broke the story Julianne apparently left her car door unlocked in a parking garage and someone stole $100,000 worth of jewelry Ryan bought for her.