The 86-year-old monarch was shown in a sequence pre-filmed by the BBC in which James Bond actor Daniel Craig arrived at Buckingham Palace in a taxi to escort the queen by helicopter to the ceremony.
A real helicopter then appeared over the Olympic Stadium during Friday’s spectacular and parachutists playing Bond and the queen jumped out, just before the real monarch entered the stadium, wearing the same outfit.
The sequence was one of the show’s highlights and was noteworthy because the queen has never acted on film before.
Nicholas Brown, the BBC’s director of drama production, said the sovereign gave a flawless performance.
“She got it in one take,” the Daily Telegraph newspaper quoted him as saying.
“That’s what she does, and she does it very well. She is a professional.”
“It was extraordinary to have the two (the queen and Craig) together with the corgis.
“The palace was terrific about the shoot and we were delighted and honoured that the queen was involved.”
Queen Elizabeth, who last month celebrated her diamond jubilee marking her 60 years on the throne, was approached in 2011 to ask if she would participate.
The sequences were filmed by Oscar winner Danny Boyle, the ceremony’s director, in March and April this year.
A Buckingham Palace spokeswoman said the queen was “very happy” to take part in the film and “immensely enjoyed” the experience.
Her majesty was “delighted to be asked to be involved in something so exceptional”, she said.
The four-and-a-half minute clip even starred three of the queen’s own corgi dogs: Monty, Holly, and Willow.
Jackie Brock-Doyle, communications chief for the London Games organisers, said chief organiser Sebastian Coe had asked the queen to appear in the film.
“Not much persuading” was required to convince her, she said.
“I think she really liked the whole concept that Danny (Boyle) had put together,” she said.
The queen, as Britain’s head of state, officially opened the Games during the ceremony.
She was back at the Olympic Park on Saturday, visiting the viewing tower, the Aquatics Centre, the Athletes’ Village and its canteen.
The queen entering the helicopter was played by “Miss Marple” actress Julia McKenzie, while the monarch jumping from the chopper was played by professional stuntman Gary Connery.
The show-stopping sequence was kept a closely-guarded secret.
The Sun newspaper ran a story largely revealing the involvement of the queen and Craig on April 1 — which led many to believe it was an April Fool’s Day joke.