The telly favourite had an emotional reunion with his co-host Declan Donnelly after he spent the summer in rehab battling his addiction to prescription painkillers. "And, we're here for the next three weeks, your hosts with the most, me and the gorgeous Holly Willoughby", the 42-year-old jokingly started.
"That is the wrong script", he said, before turning to his pal. You've put the wrong script in the thing... Nobody was sure if you'd make it or not.
I was always going to make it. "I'm back my friend - come on?" before they shared a hug.
The launch marked Ant's much-anticipated return to TV screens, following his stint in rehab over the summer.
Ant and Dec then returned to their usual jokes as they got on with the rest of the show, however, Dec couldn't resist taking another swipe at his co-star later in the show.
Ant has suffered a hard 2017, after admitting in June he had been battling a two-year addiction to painkillers after a devastating knee injury and fertility issues.
It's so good to have him back where he belongs - and what a series of I'm A Celeb it's already shaping up to be! And take them with alcohol, which is ridiculous.
Her defiant message also touched on her absence in Australia, as she added the hashtags: '#haventbeentoOzfor10years #ihaveajob #allaloadofmadeups**t #imnotestrangedthank-you #asyouwere'.
An insider told MailOnline: 'They are in bed by 5pm, so there's no partying.
'It's Ant's birthday but he is going to be working.
This year's 10 confirmed contestants met each other for the first time at a plush house and were paired together.
Referencing reports that claimed Ant could have missed the series and have been replaced by Holly Willoughby, Dec opened the show by saying: "Good evening and welcome to Australia".