The 29-year-old "Joan of Arcadia" star tied the knot on Saturday to 48-year-old "Arrested Development" actor David Cross. It's the first marriage for both of them.
Director Lance Bangs broke the news when he shared a photo of Tamblyn and Cross dancing at their reception on Instagram -- and it was later confirmed by their reps to PEOPLE.
The reception included performances by Yo La Tengo and Questlove of The Roots.
While Amber attended her "Sisterhood of the Traveling Pants" costar Blake Lively's wedding with Ryan Reynolds last month, there's no word on if the "Gossip Girl" star was in the house for Amber's nuptials.
Congrats to the happy couple!
Check out more Hollywood May-December romances in the gallery above.