Sam Smith Wears Baggy Outfit For 'Barbie' European Premiere in London

Sam Smith was all about bringing extra to the "Barbie" movie premiere across the pond ... as in, lots of extra material to complete their look.

The singer showed up to Wednesday's European premier in London rocking a crewneck with 16 XL written across the front. Unclear if that's the actual size of the gear, but it's a BIG fashion statement nonetheless.

As you can see, Sam paired the super baggy top with, what else, super baggy jeans ... so baggy, in fact, you couldn't even see their feet.

Sam's not in the movie, instead they're singing on the "Barbie" soundtrack ... with a song called "Man I Am," dropping next week, at the same time the Greta Gerwig film hits cinemas back here in the States.

Margot Robbie and Ryan Gosling, meanwhile, were on the other end of the fashion spectrum ... Ryan went with a mint green suit, and Margot wore pink once again, as she has throughout her movie promotion.

Barbie fanatics may recognize Margot's outfit inspiration ... she channeled a doll from way back in the day, "Enchanted Evening" Barbie.