TMZ has confirmed that the new parents recently purchased a mansion together in the Beverly Hills Post Office neighborhood of L.A. for a whopping $13.45 million. They own the home as joint tenants, so they're co-owners. Presumably, that means they went halfsies on the crib.

This is the first property Kylie and Travis own together and it's a beaut, with a 2,300 square foot master bedroom alone and every other luxury you could imagine, including a multi-car garage, a gym, a massage room and more -- it's right up the Kardashians' alley.

Like we've told you ... Kylie already owns a home by herself in Hidden Hills, for which she dropped $12 million. That was her fourth property, and this would be her fifth. She also just recently listed a pricey pile of dirt for $5.55 mil.

Kylie and Travis were repped by Tomer Fridman and Carl Gambino.