The television star showcased her toned and tanned pins in a picture she shared with her one million followers on Instagram ahead of the show.
In the snap, the mother-of-three can be seen adjusting the strap on her shoe in a floor length gold gown, which features a daring thigh-high slit, between rows of seats in the theatre.
Wearing her long hair in a voluminous style she enhanced her natural good looks with glamorous evening make-up.
Posing a question to her followers, she captioned the image: “Before the new series of @bgt starts (7.15pm Sat night on @itv) I’d like to know your favourite #BGT moment of the last 12 years?”
The former actress, then humorously added: “FYI I’m looking at no one while doing up my shoe – which is already done up.”
The TV judge wore a second show-stopping gown when she joined her co-star Alesha Dixon, 40, for a photoshoot to promote the ITV show.
Alesha dazzled in silver sequinned gown which showed off her phenomenal figure while Amanda opted for a plunging fishtail number in the most recent pictures to be released.
The singer’s metallic gown featured a large bow at the centre and a neckline that plunged all the way to her naval.
Wearing her hair in a sleek low ponytail, Alesha’s long legs took centre stage in wrap around skirt and sparkly sandals.