Allison Williams marries in Oscar de la Renta wedding dress

Though she plays the uptight Marnie on Girls, actress Allison Williams played the relaxed (and blushing) bride to perfection as she married her longtime love Ricky Van Veen over the weekend. A representative for the star confirmed to HELLO! that Allison and Ricky tied the knot on Saturday, with the bride wearing a couture gown by Oscar de la Renta.

Daughter of newsman Brian Williams, Allison announced her happy news on Instagram and shared a breathtaking photo of herself and her new husband Ricky strolling hand-in-hand outdoors, against a fairy tale backdrop.

9.19.15 Dress by @oscar.de.la.renta Photo by @christianothstudio

A photo posted by Allison Williams (@aw) on

Allison Williams and Ricky Van Veen married on Saturday in a ranch in Wyoming

The actress looked beautiful in her full-length gown that featured a nipped-in waist, demure high neckline and long sleeves. The handmade gown was finished with a floral overlay, and Allison, 27, topped off her romantic look with a flowing veil.

Ricky, the founder of popular comedy website CollegeHumor, was pictured admiring his new bride. The 34-year-old looked equally dapper in a dark suit and a red striped tie. Allison simply captioned the photo "9.19.15", referencing the date of their wedding.

Girls' co-stars Zosia Mamet, Lena Dunham and Jemima Kirke were all in attendance Photo: Getty Images

HELLO! has also learned that the couple exchanged vows at the Brush Creek Ranch in Saratoga, Wyoming. The star-studded guest list included Allison's Girls co-stars Lena Dunham, Jemima Kirke, Zosia Mamet and Tom Hanks' wife Rita Wilson, who plays Allison's on-screen mother.

Ricky, 34, popped the question to Allison, 27, in February of last year

Allison and Ricky announced their engagement in February 2014 after dating for three years.

For more of the latest celebrity and royal news follow us @HelloMagUS on Twitter, Pinterest and like us on Facebook.