Scarlett Johansson was just the butt of Colin Jost's jokes on 'SNL,' but wifey's not mad at hubby -- in fact, the two of them just hosted a big Xmas bash ... with A-listers in tow.

The couple threw together a major shindig Thursday in NYC at The Flatiron Room in Manhattan, and it looks like they invited all their famous pals to roll through and party before Christmas -- to which a ton of celebs happily obliged.

It was a bit of a lovers parade here ... not only were ScarJo and CoJo seen, but so too were Chris Evans and his wife Alba Baptista -- not to mention Alec and Hilaria Baldwin.

Ditto for Jon Hamm and Kieran Culkin, who were with their significant others ... and BTW, we also got a glimpse of Greta Gerwig and Noah Baumbach, who just recently got hitched. They look about as happy as can be in married life.

Anyway, other big-time hot shots were rolling solo for this thing ... like Chris Rock, Sarah Silverman, Bill Murray, Sal Vulcano and Rachel Dratch. A hodgepodge of star power, indeed.

Looks like it was an 'SNL' reunion, of sorts, and some guests/hosts were invited as well. This also confirms the obvious ... there's a helluva lot of celebs out in the Big Apple for the holidays. Compared to L.A., where it's a tad bit nippy, New York looks downright freezing.

Anyway, the only interesting thing about this is that Scarlett's clearly a good sport after getting roasted on her husband's TV show. Remember, his "Weekend Update" cohost, Michael Che, made him read a joke he'd written last week ... where he torched her "little art films."

Looks like she can roll with the punches and then some ... 'cause she ain't bent outta shape.

Good looking couple ... good looking people. That's what Xmas is all about, right?!