He was last interviewed on the ITV breakfast programme in 2017 when he was foreign secretary, and fleetingly featured on the programme in December 2019 - more on that famous incident below.
What happened when the PM last featured on GMB?
Mr Johnson appeared on the show in December 2019 when he walked away from cameras and appeared to hide in an industrial fridge in order to avoid engaging in an interview.
Piers Morgan, who presented Good Morning Britain at the time of the incident, responded to the news of Johnson’s return to the programme, tweeting: “He’s out of the fridge! If you’re doing the rounds @BorisJohnson – you know where to find me.”
While Morgan was on the show, he and Reid counted daily how long it had been since Tory ministers and Mr Johnson had been on the show.
In October last year, during the Conservative Party conference in Manchester, attempts were again made to get the Prime Minister to appear on the breakfast show.
Presenter Ranvir Singh attempted to engage with Johnson and invited him to speak on the show but she was met with a raised hand as the Prime Minister walked off.
When will the interview air?
The interview is set to take place tomorrow (3 May), on Good Morning Britain.
The programme airs on weekdays on ITV from 6am.
Who confirmed it?
Kate Garraway confirmed the interview while presenting the programme with Richard Madeley on Monday 2 May.
She said: “We’re actually going to be hearing from him, for once, tomorrow.
“Susanna Reid is going to Downing Street and their interview will be live on Good Morning Britain tomorrow from 6am, so we will be able to hear exactly what he has to say.”
A Good Morning Britain spokesperson confirmed: “In an interview with Susanna Reid at 10 Downing Street, the Prime Minister will come face to face with the presenter for his long-anticipated appearance on GMB.”