LONDON—Paul McCartney married American Nancy Shevell in London on Sunday. For McCartney, 69, the low-key ceremony at Westminster register office at Marylebone Town Hall in central London was a trip down memory lane, since he married Linda Eastman, his first wife—who was also American—at the same place in 1969.

As he emerged with the new wife on his arm, under a grey London sky, friends and onlookers cheered, showering the beaming couple with flowers and rose petals. Cameramen and fans had been waiting since early morning to catch a glimpse of the former Beatle and Shevell, 51, whom he met in 2007.

Shevell, who was married to a US lawyer for 20 years, is heiress to a New Jersey haulage firm valued at $340 million, according to media reports. McCartney, according to the 2011 Sunday Times Rich List, is Britain’s fourth-wealthiest man, with an estimated fortune of nearly $800 million.

Shevell’s wedding dress was designed by Stella McCartney, the groom’s daughter. McCartney’s marriage to former model and anti-landmine campaigner Heather Mills ended in divorce in 2008, with Mills receiving only a fraction of the divorce settlement she had demanded, which famously prompted her to throw a jug of water at McCartney’s lawyer in the courtroom.

McCartney has a seven-year-old daughter, Beatrice, with Mills. He was married to Linda McCartney for 29 years, until she died of breast cancer in 1998.