Leonardo DiCaprio is living it up in Miami, and was seen partying on Wednesday night on a Swedish billionaire’s yacht.

The “Titanic” star was spotted at biotech billionaire Ernesto Bertarelli’s floating bash aboard his $150 million superyacht, Vava II.

A source tells us DiCaprio — who split from Camila Morrone this summer, and has been linked to model Gigi Hadid — was hanging out with posse members Tobey Maguire and Helly Nahmad at the model-heavy bash hosted by his pal and de facto social director Richie Akiva.

We hear the party started after midnight and raged till 5a.m. with guests including Venus and Serena Williams, Jared Leto, art dealer Vito Schnabel, tennis pro Reilly Opelka, venture capitalist Vivi Nevo, diplomat Paolo Zampoli, and the requisite slew of “like one hundred” models.

One source told us, “There were like a hundred models. I have literally never seen more models in my life, no one was ‘normal’ looking. It was models, models, models.”

Another source tells us, “There was a group of girls that were wearing beaded dresses with nothing underneath at all, no underwear. You could see everything.”

A source tells us DiCaprio was heard chatting with Bertarelli — whose estimated worth is $8.5 billion, and whose family foundation focuses on marine conservation — about “saving the oceans.”

The…