Nancy Shevell at Old Marylebone Town Hall in London, on what would have been John Lennon's 71st birthday.
The register office is where McCartney married his first wife Linda on 12 March 1969.
McCartney, 69, and Shevell, 51, first left their home at 7 Cavendish Avenue in St John's Wood at 11.15am in a maroon Lexus car. The car took the couple, who wore dark tracksuits, to nearby Lord's cricket ground, where they went to the gym. They returned to Cavendish Avenue at 12.30pm. Asked by reporters how he was feeling ahead of the wedding, McCartney gave the thumbs up.
Speculation mounted as the day progressed, and at 3.06pm the couple once again emerged, with McCartney's daughter Beatrice, 7, a flower girl at the wedding. McCartney sat in the front of the Lexus alongside the driver, while Shevell was in the back with Beatrice.
The couple arrived at Old Marylebone Town Hall at 3.20pm. Shevell wore a simple ivory dress, designed by Stella McCartney, and a white flower in her hair.
A tent was erected in the driveway of the Cavendish Avenue house two days prior to the wedding, and champagne, flowers, party decorations and furniture were brought into the house. Refrigerators in the grounds were filled with non-vintage Dumangin Grande Reserve champagne.
Just 30 guests attended the ceremony, among them Ringo Starr and his wife Barbara Bach. McCartney's best man was his brother Michael.
They exchanged rings reportedly from Los Angeles jeweller Neil Lane. Following the wedding, a party was held at Cavendish Avenue, where guests were served vegetarian food.
The wedding was conducted by superintendent registrar Alison Cathcart, at a cost of £1,540. The couple filed their notice of intent to marry on 14 September 2011 at Old Marylebone Town Hall.
The best thing about being a registrar is the knowledge that in one moment you have changed people's lives, and I'm delighted that Paul and Nancy have chosen Marylebone Town Hall for their special day.
I am honoured to be conducting the ceremony and will get to see the look of joy on both their faces when I declare them husband and wife.
Alison Cathcart
The marriage is McCartney's third and Shevell's second. His first wife Linda died of breast cancer in 1998; he married Heather MIlls in 2002, but separated in 2006 and divorced two years later.
Shevell was married for over 20 years to US attorney Bruce Blakeman. She serves on the board of New York's Metropolitan Transportation Authority, and is a vice president of a New Jersey-based trucking company owned by her father.
