The home that once belonged to the soon-to-be youngest self-made billionaire is on the market again for a cool $3,599,000. Kylie bought the Tuscan villa back in 2015 when she was just 17 years old. The house got a complete makeover and it's a beaut.

The 5-bedroom, 6.5-bathroom house is inside the exclusive gated community of The Oaks in Calabasas. You may recall ... Kylie paid $2.7M in 2015 and sold it 2 years later for $3.15M. It's got all the bells and whistles a future billionaire would want and need.

It's got a media room and detached casita ... plus a white stone fireplace and French doors that open up to the sprawling pool grounds. There's also a gourmet chef's kitchen with Viking appliances that would make any celeb chef go wild. And, if you're into Kylie Cosmetics ... enjoy the optional ensuite bedroom, which was transformed into an ultra-luxe glam room with lighted vanity, mirrored walls and custom drawers.

April Lopez and Jay Ravnikar of The Agency rep the seller.

For Kylie ... buying cribs in the single-digit millions is kind of in her past. As we've reported ... her latest acquisition is a huge lot for a record $15 million in Hidden Hills. There's also the whopping $36.5 million Holmby Hills estate she scooped up earlier this year. Not to mention the other properties in Hidden Hills.