The legendary actor dropped in on Timothée over in the United Kingdom for Tuesday's debut of Chalamet's new movie, "A Complete Unknown," at the Ham Yard Hotel in London, England

Tom and Tim shook hands and posed for some photos together ... in one shot of just the two of them, Tom is pointing at Tim and has one hand over his shoulder.

It's pretty cool to see Tom and Timmy together here ... and it's kind of like Tom is passing the torch in a way ... though that's not to say Tom is going to stop being an action star anytime soon.

Tom and Tim also snapped a group shot with the rest of the cast ... including Monica Barbaro, Elle Fanning and director James Mangold.