Jeremy Paxman will host Channel 4's 2015 General Election coverage.
The 64-year-old quit BBC 2's Newsnight in June after presenting the show for 25 years.
Paxman said: "There are new and interesting questions to ask about the way we choose our governments. This should be fun."
The chief creative officer of Channel 4, Jay Hunt, said: "Jeremy is a compelling presenter and makes truly unmissable TV for those big political moments. His sense of mischief and danger make him a fantastic fit with Four."
Jeremy Paxman bowed out of Newsnight after 25 years with a parting joke, bringing his sardonic style to a spoof presenting the weather.
His final show saw Boris Johnson become the last person to face the veteran broadcaster's abrasive interviewing technique, but the London mayor had only warm words to say about him.
As he signed off the BBC2 programme for the final time last night, Paxman told viewers: "I'll just say thank you for watching Newsnight. I hope you continue to enjoy it. Goodnight and goodbye."
Earlier, Michael Howard appeared on the programme and asked if he would like to repeat a question 12 times, as he famously did over claims the former Home Secretary "threatened to overrule" a director over the possible sacking of a prison governor.
Paxman ended the programme with a weather forecast saying: "And tomorrow's weather - more of the same. I don't know why they make such a fuss about it."
Jeremy Paxman gained a reputation for never shirking the difficult questions in his interviews with politicians on Newsnight, such in this infamous 1997 grilling of future Tory leader Michael Howard, who was asked exactly the same question several times.
The BBC thanked Jeremy Paxman for agreeing to stay on at Newsnight to help its new editor "following a difficult period" which saw the show lambasted after it pulled a planned expose of Jimmy Savile's sex crimes.
A corporation spokeswoman said: "The BBC is immensely grateful for this gesture, which is entirely in keeping with his outstanding contribution to both Newsnight and, over four decades, the BBC itself."
Paxman will present his last Newsnight show in June.
Jeremy Paxman will continue to present University Challenge despite stepping down as the host of Newsnight, the BBC has said.
Paxman has fronted the quiz show since 1994, when it was revived by the BBC having previously been an ITV show presented by Bamber Gascoigne.
Jeremy Paxman said he is quitting the flagship current affairs show Newsnight and would like to "go to bed at much the same time as most people".
The broadcaster, one of the most familiar faces on the BBC2 show, is one of the corporation's biggest stars.
In a statement, he said: "I have decided it is time to move on from Newsnight. After 25 years, I should rather like to go to bed at much the same time as most people.
"This was a decision I reached - and informed the BBC of - last July. I shall work out the remainder of my contract and will not seek another.
"It's been fun. I have had the pleasure of working with lots of clever, creative and amusing people. I think I've been lucky and wish the programme well."
The BBC's Director General Tony Hall hailed Jeremy Paxman's "rare and dazzling talent" after the presenter announced he was quitting the BBC show Newsnight.
Jeremy Paxman said he had "no idea" what he was going to do next in an "emotional" speech at the BBC, his Newsnight colleague Mark Urban tweeted: