The ABC's political editor Chris Uhlmann has announced he is leaving the national broadcaster to move to the Nine Network.

After almost 20 years with the ABC, Uhlmann will move to fill the shoes of veteran Nine journalist Laurie Oakes, who recently retired.

Uhlmann joined the ABC in 1998 and has been political editor for the ABC — across television, radio and digital — since 2015.

"It is hard to leave the ABC. I do it with a heavy heart and a profound sense of gratitude. I go simply because I am seeking another challenge and believe that the time is right," Uhlmann said.

"The ABC is a national treasure. It has given me opportunities I never dared dream of, is home to some of the best journalists in the world and many of my best friends.

"I have not forgotten that the ABC took a risk appointing me to parliament in 2006 and remember what I said at the end of my [second] interview: 'I promise I won't let you down.'

"I have tried to honour my side of that pledge and know the ABC has honoured its end of the bargain.

"I will not be a commentator on what you do but I will be avidly watching and listening.

"Godspeed."

Sorry, this video has expired Trump 'has no desire and no capacity to lead the world', Chris Uhlmann says

Just last month Uhlmann's two-minute report for ABC's Insiders on Donald Trump's appearance at the 2017 G20 Hamburg summit went viral, and was viewed millions of times within the United States.

He has won a Walkley award for broadcast interviewing and has also co-written a series of successful political thrillers that were later turned into a mini-series.

Uhlmann was formerly a seminarian and a security guard, before becoming "the world's oldest copy kid" for the Canberra Times at the age of 29.

He has worked for 7.30, AM and was recently involved in producing a special report on Chinese influence for Four Corners.

7.30's current political correspondent Andrew Probyn will fill the role of political editor from Monday, and David Lipson from Lateline will fill in for Probyn as 7.30 political correspondent.