The event, being billed by the station as the biggest live stand-up show yet in the UK, will be staged in front of 14,000 people at the O2 Arena.
The bill of 20 comics for the March 30 show also includes Alan Carr, David Mitchell, Rich Hall and Bill Bailey.
Channel 4's Comedy Gala, to be filmed and screened by the station in April, will raise cash for Great Ormond Street Hospital.
Jonathan is due to leave the BBC in July when his contract runs out, and Channel 4's programme chief Julian Bellamy recently said he had been "in touch" with the presenter. The star's agent is the executive producer of the event.
Other stars taking part in next month's show are Jo Brand, Lee Evans, Mark Watson and Omid Djalili. A number of the stars taking part such as Jo, Rob, Omid and Jack are better known for their BBC pedigree.
Channel 4's head of entertainment, Justin Gorman, said: "From Peep Show to Chatty Man to The Inbetweeners - Channel 4 has impeccable comedy pedigree, and we're incredibly proud of the talent we have on the channel.
"We are very pleased that so many other comedians and celebrities are joining us for what we fully intend to be the comedy event of the year."
Funds from the event will pay for new anaesthetic rooms at the children's hospital.
Tickets go on sale from Friday.