Jon Hamm Marries Anna Osceola in 'Mad Men'-Inspired Wedding

Jon Hamm finally tied the knot -- and he did it with a former 'Mad Men' costar, no less ... with a lot of other nods to the show that made him super famous.

The actor married Anna Osceola Saturday after getting engaged last year ... and after dating for 2 years. They'd actually met on the set of 'Mad Men' in 2015 ... and apparently circled back with each other after Jon split with his longtime partner, Jennifer Westfeldt.

Now, as for the nuptials themselves ... absolutely stunning. Jon and Anna got hitched at beautiful Anderson Canyon in Big Sur -- so, yes, it was a seaside wedding of sorts.

The reason the Big Sur location is significant isn't lost on fans of 'MM' -- the series ended with Don Draper there having a rediscovery of himself ... and the final shot shows Jon's character stumbling across an epiphany for the iconic "Hilltop" Coke ad of 1970.

Nice little nod, obviously -- but the guest list was just the cherry on top for a "Mad Men" flashback. John Slattery showed up to congratulate his old costar, and there was even a hint of "Mad Men"-themed cocktails on hand as an homage. Lord knows those boys drank!

Other A-listers in attendance ... Billy Crudup -- who just recently got married himself -- plus Paul Rudd, Tina Fey, and others. Their walkup song was James Bond-linked too ... with a band playing the theme to "You Only Live Twice." Indeed, it was all 1960s fare here.

As for the bride and groom ... they looked great. Jon was incredibly dapper in his tux -- and Anna wowed with her flowing gown. Everyone else was dressed to the nines as well.