The Girls star began dating CollegeHumor founder Ricky Van Veen in 2011 and the pair got engaged in February 2014.
Yesterday the happy couple said 'I do' at Saratoga's luxury Bush Creek Ranch, reports Page Six. Guests included her Girls co-stars Lena Dunham, Zosia Mamet and Jemima Kirke, as well as Katy Perry and Seth Meyers. Tom Hanks apparently officiated the ceremony as his wife Rita Wilson sat in the crowd, and John Mayer performed for the newlyweds.
Allison's news anchor father Brian Williams walked her down the aisle, with the actress said to have dazzled in an Oscar de la Renta gown.
It seems the couple were keen to keep details of their nuptials quiet, as insiders told the publication even guests were unsure of what to expect.
“Guests were asked to fly into Denver, where they would be driven around three hours to the wedding location, but nobody knew where it was going to be," the source said.
The 27-year-old beauty previously spoke of how taken back she was when Ricky popped the question while talking to her good pal Seth Meyers, adding she loves her engagement ring.
"I was completely surprised. A total surprise, the best kind of surprise," she laughed.
"I'm obsessed with it. I stare at it a lot."