Bassey, 76, wearing a gold dress, gold necklace and gold earrings, appeared on stage following a film and music tribute to the Bond movie franchise, which began in 1962 with the first Bond film "Dr. No," starring Sir Sean Connery.
Last year, "Skyfall," the 23rd installment of the Bond series - the longest-running motion picture franchise in history - was released and became the highest-grossing Bond film, crossing the $1 billion mark at the global box office.
British singer Adele, 24, who swept the Grammys last year with her soulful heartbreak album "21," continued the Bond theme later in Sunday's Oscar ceremony with her rendition of the Bond theme "Skyfall," which has won the Golden Globe and Critics Choice accolades for Best Song this year.
Bassey has become synonymous with the Bond franchise, singing the theme songs not only for "Goldfinger," but 1971's "Diamonds are Forever" and 1979's "Moonraker."
The Welsh diva was preceded on the Oscars stage by actress Halle Berry, who appeared as Bond girl Jinx in the 2002 movie "Die Another Day," starring Pierce Brosnan as Bond.
"Tonight, we celebrate the 50th anniversary of James Bond in motion pictures," Berry said, adding that the music of the films "is as inextricably linked to Bond as the martini, exotic cars and Pussy Galore."
Halle, who won a Best Actress Oscar for "Monster's Ball" in 2001, was asked about her role as a Bond girl on the red carpet before Sunday's Oscars ceremony.
"I've not been more proud to be part of a franchise than that one," Berry said.
Connery went on to play the British secret service agent five more times after "Dr. No" until 1971's "Diamonds Are Forever."
English actor Sir Roger Moore embodied Bond seven times, including 1973's "Live and Let Die," 1983's "Octopussy" and 1985's "A View to Kill."
Actors George Lazenby, Timothy Dalton and Pierce Brosnan also played the lead role.
Bond films have historically received only a handful of Oscar nominations, mainly within the technical or music categories.
This year, "Skyfall," starring Daniel Craig in his third appearance as Bond, landed five nominations including Best Cinematography, Best Original Song and Best Original Score.