He was reunited with his long-time on-screen partner Declan Donnelly for the first day of auditions at the London Palladium.
On Twitter before the show, the pair posted a photo captioned: “#BGT 2019. Audition day 1. The boys are back in town!”
It comes after McPartlin stepped away from his TV work in March last year following a drink-driving charge, leaving Donnelly to front the Britain’s Got Talent live shows alone.