Nancy Shevell and Paul McCartney were all smiles as they left the Marylebone Registry Office. Photo: PA
The Beatle and his blushing bride couldn't stop beaming as they left the ceremony venue, where Paul married his first wife Linda in 1969.
Nancy, 51, looked stunning in a simple, long-sleeved ivory dress with button detailing down the front, created by Paul's designer daughter, Stella McCartney.
She kept her hair loose, prettying it up with a floral accessory, and carried a bouquet of roses.
The happy couple were met at the top of the registry office steps by his daughter Beatrice, who made a cute flower girl.
They tied the knot before 30 special guests, including Paul's fellow Beatle Ringo Starr, and will enjoy a reception in the garden of their north London home.
Sir Paul has written a song especially for Nancy that he is set to serenade her with at the celebrations, which take place on what would have been the 71st birthday of his late Beatles bandmate, John Lennon.
It is thought Paul will also sing Let it Be, because it is his new bride's favourite.
The couple exchanged rings from LA-based jeweller Neil Lane, and will celebrate at the reception with Dumangin Grande Reserve Champagne.
Following the north London reception, Paul and Nancy, who are worth a combined £700 million, will fly to the Hamptons - the exclusive seafront hotspot near New York where they both own homes - for a second celebration.
Congratulations to the happy couple.
See all the action from the wedding in the video below.