The BGT judges arrived at The Lowry Theatre, Manchester, and strutted down the red carpet ready to check out the northern city's talent.
Amanda looked gorgeous in a figure-hugging dress, which featured a wavy pattern of green and turquoise hues and a black middle waist. The mum-of-two completed the look with a pair of pointed nude heels.
Her honey-blonde tresses had been styled into a voluminous blow dry, while Amanda's make-up finished off the look with flawless skin and a nude pout.
New mum Alesha opted for a different style than usual by experimenting with a pinstripe suit and even flashing a hint of her orange bra underneath.
The 35-year-old even coordinated her skyscraper heels with her underwear by opting for a fierce pair of orange-hued shoes!
The former Mis-Teeq singer completed her glam look with corkscrew curls and lined her peepers with dramatic kohl, as well as some seriously fluttery lashes.
David Walliams also made an appearance on the red carpet but unfortunately, it was a no-show for Simon Cowell who has been struck down with a nasty cold.
Despite being in his sick bed, Simon did, however, confirm his return to The X Factor later this year.