The TV personality and actress styled her hair swept back off her face and looked chic in a white Alexander McQueen blazer and matching pencil skirt as she posed on the red carpet and greeted fans.
Holden, also donning red lipstick and snakeskin Louboutin heels, later revealed that her new style may have been inspired by Sex and the City's saucy Samantha Jones (played by Kim Cattrall) as she tweeted: "Homage to Samantha Jones? #satc."
Meanwhile fellow judge Alesha Dixon, who gave birth to her daughter Azura Sienna in October, added colour in a burnt orange long-sleeved top and high-waisted skirt as she arrived at Birmingham's International Convention Centre.
Simon Cowell opted for a pair of his trademark jeans and a grey ribbed jumper, while David Walliams looked smart in a pinstripe suit.
Holden also shared a snap on Twitter of Walliams holding a blow-up doll which was made to look like Cowell - complete with chest hair.
Last week, the judges were left open-mouthed after a daring performance from a group of seven death-defying stunt bikers during the try-outs in Cardiff.
Auditions have yet to take place in Manchester and London.
Britain's Got Talent returns to ITV later this year.