The short teaser appears to feature the pair's voices, shouting out: "Let's get ready to jungle!"
It comes months after one half of the much-loved duo, Ant McPartlin, entered rehab following his struggle with a two-year addiction to super-strength painkillers that followed a knee operation in 2015.
The ITV's director of television said in August that McPartlin was doing "really well" and he expected him to return to the show.
Thrilled with the latest update, one delighted show fan responded: "Oh my goddddd! Yessssssss! Finally...the @antanddec drought is gonna end! CAN'T BLOODY WAIT! #ImACeleb."
"Yep, that's the boys both of them thank goodness," added another.
One concerned viewer posted: "As long as #antmcpartlin is ok and ready to come back."
"My boys are back," said one, while another hoped: "Literally the highlight of my year lol cant wait to see ant and dec back together ."
The ITV show, which sees a collection of celebrities face a series of stomach-churning tasks as they camp out in a jungle, was won last year by Gogglebox star Scarlett Moffatt.
This year she will return to present ITV2's spin-off programme, I'm A Celebrity...Extra Camp, alongside 2016 runner-up Joel Dommett and long-running host Joe Swash.