The football manager is rumoured to be appearing on the ITV show, which will be fronted by Declan Donnelly and Holly Willoughby.
Harry was dressed in casual attire for the long-haul flight as he wore a pair of black jeans teamed with a fleece.
The 71-year-old attempted to keep a low profile as he walked through Heathrow airport to jet off to Brisbane.
If confirmed, his appearance on I’m A Celebrity… Get Me Out of Here! will follow a number of football stars who have also took part including Jimmy Bullard, Wayne Bridge, Neil “Razor” Ruddock.
Yesterday, The Sun Online reportedly revealed which celebrities would be heading Down Under this series.
Former EastEnders actress, Rita Simmons, who played Roxy Mitchell, is rumoured to be joining the show after her character got killed off the soap two years ago.
Another soap star, Sair Khan, who plays Alya Nazir in Coronation Street, is set to be joining Rita.
The Chase’s Anne Hegerty and Emily Atack, who played Charlotte Hinchcliffe in The Inbetweeners, may also be making their way to Australia in the following days.
Other stars who have reportedly signed up include DIY SOS presenter, Nick Knowles, X Factor 2014 runner-up, Fleur East, The Vamps star James McVey and Hollyoaks actor Malique Thompson-Dwyer.
The publication reported there’s one more surprise star set to enter the jungle with their identity being kept top secret.
Another two celebrities will also join camp later in the series after it begins next Sunday.
Dec, 43, will be presenting his first series of I’m A Celebrity… Get Me Out of Here! without his sidekick Ant McPartlin, who has stepped down from his TV commitments.
The Geordie will be co-hosting the reality show beside This Morning presenter, Holly Willoughby.
Despite being Down Under without Ant, 42, Dec remained in good spirits as he enjoyed a shopping trip with his wife Ali Astall today.
The star was all smiles on his outing and he cut a casual look for as he wore a navy polo shirt matched with a pair of grey shorts.
The couple, who welcomed their first child, daughter Isla, together in September, seemed to be stocking up on necessities for their stay as Ali carried some kitchen roll.
Holly was spotted making her way to Australia yesterday and will be joining her co-star with her husband Dan Baldwin and their three children, Harry, nine, Bella, seven, and Chester, four.
Extra Camp hosts, Joe Swash, Joel Dommett and Scarlett Moffatt were the first stars to head Down Under last week.
Yesterday, former I’m a Celebrity… Get Me Out of Here! winner Scarlett reunited with Medic Bob from the show.
The two posed for a sweet picture together as they caught up before the next series begins.
Sharing the snap to her Instagram account, Scarlett wrote: “It’s official I’m in the jungle!! My medic bob is here #jungle #doctor #imacelebrity.”
I’m A Celebrity… Get Me Out of Here! begins Sunday 17 November on ITV.