The Made In Chelsea star, 23, was pictured walking arm-in-arm with her father before the wedding ceremony began at Babington House near Frome.
Millie opted for a white gown with a waterfall hemline, a train and lace detailing around the shoulders. The dress had cap sleeves and she wore simple peep-toe heels underneath.
The star styled her hair in a pretty braid across her head and topped off her look with a simple tiara and shoulder-length veil. She carried a small posy of pink flowers, including roses.
Millie's father looked extremely dapper in a three-piece suit with tails and proudly linked arms with his daughter before giving her away.
Professor Green, meanwhile, kept it cool in a blue suit, white shirt and navy tie. He wore a pink rose buttonhole to match his bride.
Millie's best friend and Made In Chelsea co-star Rosie Fortescue was also at the wedding, along with several other famous faces.
Lily Cooper and her husband Sam were pictured arriving for the ceremony along with TV presenter Miquita Oliver.
Despite Rosie being there, Professor Green previously said that he did not want the Made In Chelsea cast at their wedding.
Some have sent their congratulations, including Cheska Hull. She tweeted: "Have an amazing day @millsmackintosh thinking of you xxx"
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