The program, which was released in the United States last year, allows users to perform Yoga, jogging, and balance exercises as well strength-building and hula routines.
"I find exercise is a bit like meeting an old lover," Mirren, 65, says in the ad. "You're really pleased to see him and you get tired of him really quickly and you remember why you didn't like him in the first place. With the Wii, it's like having a new lover every day. What could be better for a girl?"
Mirren recently played a femme fatale in the spy film "Red" with Bruce Willis and Morgan Freeman. She can be seen next with Russell Brand in the comedy movie "Arthur", which is set for release in 2011.
Check out Helen Mirren in an ad for Nintendo's Wii Fit Plus game.