Andress was born in Ostermundigen, Bern, Switzerland, the daughter of Anna, who was Swiss, and Rolf Andress, a German diplomat who was expelled from Switzerland for political reasons. He disappeared during World War II. Andress has four sisters and one brother. She is fluent in English, French, Italian, and her native German (Swiss German). The young Andress started her career as an art model in Rome, which led to her first roles in the Italian movie industry.

Andress became famous as Honey Ryder, a shell diver and James Bond's object of desire in Dr. No (1962), the first Bond movie. In a well-known scene, she rises out of the Caribbean Sea in a white bikini. The scene made Andress the "quintessential" Bond girl, and is now considered iconic. "My entrance in the film wearing the bikini on that beautiful beach made me world famous as 'the Bond girl'", she said, and the bikini from this "classic moment in cinema and Bond history" sold for £35,000 at auction in 2001. In 2003, in a UK Survey by Channel 4, her entrance in Dr. No was voted #1 in "the 100 Greatest Sexy Moments". In 2007, Australian series 20 to 1 ranked her entrance in Dr. No as the #2 Sexiest Movie Moment.

Andress won a 1964 Golden Globe award for New Star of the Year for her performance in Dr. No. Her voice was provided by Nikki van der Zyl while the famous calypso was sung by Diana Coupland. In 1965, she posed nude for Playboy.

Andress co-starred with Elvis Presley in the 1963 film, Fun in Acapulco, with Frank Sinatra in 4 for Texas (1963), opposite Marcello Mastroianni in The 10th Victim (1965), and as the countess in The Blue Max (1966). She also appeared in the Bond satire Casino Royale (1967) as Vesper Lynd, an occasional spy who persuades Evelyn Tremble, as played by Peter Sellers, to carry out a mission. Her heavy accent was dubbed over in Dr. No, but she used her own voice in Casino Royale.

In 1981's Clash of the Titans, she co-starred with Harry Hamlin. In 1995, Andress was chosen by Empire magazine as one of the "100 Sexiest Stars in film history."

In 1957, Ursula Andress married actor/director John Derek. The marriage ended in divorce in 1966. Andress dated many of Hollywood's leading men including co-stars Marlon Brando and James Dean. In 1980, she had a son, Dimitri, with American actor Harry Hamlin, her co-star in the film Clash of the Titans. On May 18, 2006, on the occasion of the inauguration of the Swiss Consulate General in Scotland, Ursula Andress celebrated her 70th birthday on board the Royal Yacht Britannia in Edinburgh in the presence of an international crowd of celebrities.