The Wolf of Wall Street star, 39, and his Victoria's Secret love, 21, are said to be living in the actor's home in New York City.
"Leo bought the apartment [in March] and quickly moved Toni in with him," a source told In Touch. "It seems like they're really enjoying living together."
Leonardo DiCaprio and Toni Garrn
The insider added that Leonardo and Toni, who have been dating for nearly a year, always look "happy" and "relaxed" when spotted in the residential block.
Leonardo is clearly a fan of the luxury Battery Park City building as he previously occupied a bachelor's pad there. The onscreen heartthrob exchanged his old flat for a 2,300-square-foot unit which he and Toni could live in.
While the pair are happily settled, the source added that it was solely Leonardo who purchased the £4.7million flat. Leonardo's other properties in his native America include a large beachfront estate in Malibu, California, and a £3million Palm Springs holiday home.
Leonardo on the set of The Wolf of Wall Street
The Titanic actor has previously dated a host of beautiful models including Brazilian beauty Gisele Bundchen and Israel-born Bar Refaeli.
Speaking to Gayle King during a CBS This Morning interview in February, the Oscar-nominee revealed that he looks for "humility, a sense of humour and not a lot of drama" in a potential love interest.
Leonardo also revealed that he's coming round to the idea of settling down permanently. "The truth is, it's gonna happen when it's gonna happen," he said on the subject of marriage. "I'm just gonna let it happen naturally. I really am. That's the way to do it, I feel. And when it's right, it's gonna be right."