Following the film's official unveiling earlier this week, Harris said she has undertaken a strict fitness regime in preparation for her role as field agent Eve.
"I've been doing yoga three times a week, stunt driving and firing machine guns - which I discovered I had a real taste for," Harris told People this week. "I'm raring to go!"
The Pirates of the Caribbean star was originally rumoured for the role of Miss Moneypenny, who has been absent from the franchise since 2002's Die Another Day.
Daniel Craig will reprise his role as James Bond for the third time, opposite the returning Judi Dench as M.
Joining them in Skyfall are Javier Bardem, Ralph Fiennes, Albert Finney and new Bond girl Bérénice Marlohe.
Directed by Sam Mendes, Skyfall is expected to begin filming later this year for release on October 26, 2012.
Watch the official press conference announcement of Skyfall below: