In a video posted on X, the troublesome former PM said he was “excited” to sign up to the “remarkable” new channel – boasting that the show would allow him to share his “unvarnished views” on politics.
In a warning to Rishi Sunak, the ex-Tory leader said he would talk about “everything from Russia to China to the war in Ukraine, how we meet all those challenges, to the huge opportunities that lie ahead”.
GB News said Mr Johnson would cover the upcoming UK and US elections. The ex-PM said he wanted to discuss “why our best days are yet to come” and why he believes people “want to see more global Britain – not less”.
He joins a series of former Tory colleagues – including ally Sir Jacob Rees-Mogg, current deputy chair Lee Anderson and fellow Brexiteer Nigel Farage – with their own shows at the controversial channel.
The ex-Tory leader has been a constant thorn in the side of Mr Sunak since he was kicked out of No 10 by his own party last summer.
Mr Johnson attacked Mr Sunak’s Brexit deal for Northern Ireland, blasted his successor’s smoking ban, condemned the move to axe HS2, claimed No 10 was failing to provide weapons wanted by Ukraine and rowed with the government over the release of his Covid-era WhatsApp messages.
The ex-PM sensationally quit as an MP in June after claiming he was the victim of a “witch hunt” over his Partygate scandal – having been found to have deliberately lied to the Commons about his knowledge of rule-breaking.
He was widely perceived to have jumped before he was pushed, as the privileges committee later revealed he would have faced a 90-day suspension if he were still MP.
Although he no longer enjoys his £86,000 salary since quitting his Uxbridge seat, Mr Johnson is said to have secured a “very-high six-figure sum” to write his weekly column for The Mail.
The Tory leader has now earned almost £5m over the past year – mostly from the huge fees charged for speaking at events overseas after he was kicked out of Downing Street.
As well as making around £4.2m from speaking events, Mr Johnson struck a £510,000 deal with HarperCollins in January to pen a memoir “like no other”.
It is not clear whether Mr Johnson will carry on with his Mail column – in which he has written about his dog Dilyn, the Elon Musk-Mark Zuckerburg row and his love of cheddar cheese – after starting with GB News.
Mr Johnson sought advice from Whitehall’s appointments watchdog before taking up the job. The Advisory Committee on Business Appointments said it did not have any “particular concerns” about the role.
He now joins Sir Jacob, Mr Anderson, former Conservative pensions minister Esther McVey and senior Tory backbencher Philip Davies as presenters on GB News.
Amid concern about a Tory takeover of the channel, the regulator Ofcom ruled that a GB News interview with chancellor Jeremy Hunt by two fellow Conservative MPs breached impartiality rules.
The channel said Mr Johnson would be joining as a “presenter, programme maker and commentator”, adding that he would be playing a “key role” in the coverage of both the upcoming UK and US elections.
News of his latest gig comes as former Tory chancellor George Osborne claimed that “disgusting and misogynistic” WhatsApps sent by Mr Johnson and his former adviser Dominic Cummings will come out at the Covid inquiry.
Mr Osborne said he understood that there would be “staggering” messages shared at upcoming hearings – with the ex-No 10 strategist Mr Cummings set to appear next week.
Mr Johnson is set to give evidence to the public inquiry next month, following the long-running saga over the release of his WhatsApp messages to senior advisers and ministers.
Mr Osborne told his own Political Currency podcast that WhatsApp messages would show what a “complete nightmare” it was to work under Mr Johnson at Downing Street during the Covid crisis.