He also revealed yesterday that he will not take part in this year’s I’m A Celebrity...Get Me Out Of Here! leaving Donnelly, 42, to present it alone for the first time in 15 years.
McPartlin, also 42, announced he is taking a break from the small screen until 2019 while seeking treatment for his drink and prescription drug addictions.
He and Donnelly have jointly decided to pull next season’s Ant and Dec’s Saturday Night Takeaway but added that it will return to the screens in 2020.
The star said that he will not be heading Down Under to the jungle with his sidekick to film the ITV show.
He has been off television since March after he was arrested for drink driving.
McPartlin was hit with a £86,000 fine and handed a 20-month driving ban after pleading guilty to the offence, which left a four-year-old girl needing hospital treatment.
It led him to take time out from presenting and go on to seek treatment for addiction.
He pulled out of the last two episodes of Saturday Night Takeaway and did not present the live shows of Britain’s Got Talent this year.
McPartlin added: “My recovery is going very well and for that to continue, having spoken to Dec and ITV, I have made the decision to take the rest of the year off.
“I’d like to thank both Dec and ITV for their continued support and I look forward to getting back to work in the new year.”
Donnelly, due to become a father for the first time with his wife Ali, 40, in September, said: “Whilst I am obviously sad at the thought of being without my best friend in Australia this year, I am proud of the work Ant has been doing privately and I am fully supportive of his decision.
"I’m looking forward to us both being reunited on screen in 2019.”
Donnelly hosted the final episodes of ITV series Saturday Night Takeaway without McPartlin earlier this year.
In a statement the duo said “they will instead bring the show back in 2020, bigger and better than ever”.
Donnelly also hosted the live shows of Britain’s Got Talent without his TV partner, although McPartlin appeared in the pre-recorded auditions.
The duo has fronted Britain’s Got Talent together since 2007.
ITV director of television Kevin Lygo said: “ITV is completely supportive of Ant taking as much time as he needs in his recovery and of this mutual decision to rest Takeaway in 2019.”
McPartlin has wrestled with a two-year addiction to painkillers, which led him to being admitted to rehab last year.
He had damaged his knee in 2014 and underwent a botched operation the following year leading him to be in severe pain.
McPartlin pleaded with his wife Lisa, 41, to get him to hospital in June of last year after bingeing on Tramadol, morphine and alcohol while recovering from a second knee operation.
He admitted to putting her through hell but he refused to move back into their west London home – and instead moved into a bachelor pad around the corner.
Lisa, a Strictly Come Dancing make-up artist, had originally hoped that the couple would be reunited.
But in January McPartlin revealed he was leaving her.
He has since moved away from Chiswick and is living in the area of New Malden to be closer to his new love and former personal assistant Anne-Marie Corbett, 42.