Timothée Chalamet Crashes Look-Alike Contest, Fans Go Wild

Timothée Chalamet supporting fans calling themselves by his name ... pulling up to an impromptu look-alike contest in NYC -- and, driving the crowd wild.

Here's the deal ... an unofficial Chalamet look-alike contest took place in Washington Square Park Sunday, with a massive crowd coming out to watch the spectacle.

The winner of the contest was supposed to make just $50 ... but, it seems participants got a second reward too -- a meeting with the "Dune: Part Two" star.

Watch the clip currently going viral on social media ... one of the look-alike participants is standing in front of a white balance screen when Tim comes rolling in from the side, wearing a remarkably similar outfit to his counterpart.

It takes the crowd a second to put two and two together here -- there are quite a few Chalamet Charlatans running around, after all -- but, once they do there's a lot of excited cheering and hugging.

Chalamet lives in New York City ... so, unclear if he knew about the contest in advance or if he heard what was going down and ran over on a whim -- but, either way, a fun moment for some of his biggest fans.

BTW ... local outlets say cops ultimately had to break up this contest -- with a police spokesperson saying at least one person was detained. Hopefully, Timothée made it out alright.