Leonardo DiCaprio had a titanically good time in NYC this weekend … clubbing and chatting with a woman who looks like his girlfriend.

The actor hit a club in the Big Apple … customary baseball cap pulled low over his eyes — though he went sans facemask while on the dancefloor at least.

Leo’s chatting up a lady in these vids … and, though it’s hard to tell who it is, it very well could be his GF, Vittoria Ceretti.

As you know … Leo and his Italian model GF have been hanging out quite a bit in recent months — hitting the Cannes coast for a scantily-clad yacht trip just last month.

Outlets first started connecting the two in August of last year … so, it seems they’re right around the one-year mark in their coupling — and, it still seems to be going strong.

Unclear why Leo’s in town … but it seems likely he’s stopping in NYC for New York Fashion Week — one of the biggest events for models and fashionistas.