The UK was runner-up in the 2022 contest.
But speaking to reporters at RAF Brize Norton after returning from an unannounced visit to Kyiv, Mr Johnson said he believed it should be possible for the music contest to go ahead there, despite the ongoing conflict with Russia.
“I have just been to Kyiv. I won’t say it is completely jiving and buzzing and popping but it is far, far more lively. People are much more confident. People are out in the streets eating in cafes and restaurants in a way that they weren’t a even few weeks ago,” the Prime Minister said.
“The Ukrainians won the Eurovision Song Contest. I know we had a fantastic entry, I know we came second and I’d love it to be in this country.
“But the fact is that they won and they deserve to have it. I believe that they can have it and I believe that they should have it. I believe the Kyiv or any other safe Ukrainian city would be a fantastic place to to have it.”
On Friday, Glasgow, London and Manchester were among cities to have thrown their hats into the ring to host the Eurovision Song Contest if it comes to the UK next year.
No final decision has been made but a number of regional figures have suggested their city is best suited to play host.
Mayor of London Sadiq Khan tweeted: “Londoners would welcome Eurovision with open arms.
“We’re ready to step up and support Ukraine by hosting a contest that pays tribute to and honours the Ukrainian people, and also celebrates the very best of Britain too.”
The event could take place at either the 20,000-capacity O2 Arena or the 12,500-capacity OVO Wembley Arena.
Scotland’s First Minister Nicola Sturgeon voiced her support for Glasgow as the home of the contest.
She said on Twitter: “We wish @Eurovision could be in Ukraine but understand that in circumstances this isn’t possible.
“However, I can think of a perfect venue on banks of the River Clyde!! @scotgov is happy to discuss with BBC, @GlasgowCC @EBU_HQ and others.”
And Scottish Labour leader Anas Sarwar tweeted: “I agree with @NicolaSturgeon on this. Wish the circumstances weren't so, but for an alternate venue, our fantastic city would host a #Eurovision to remember. Glasgow would be ready with open arms.”
However, Lothian Tory MSP Miles Briggs said Eurovision 2023 should come to the Capital, pointing out Edinburgh had previously hosted the contest 50 years ago and highlighting the city’s links with Kyiv.
He said: "It is understandable that sadly Ukraine cannot plan to host Eurovision 2023. Edinburgh successfully hosted the 17th Eurovision Song Contest in 1972.
“Edinburgh and Kyiv have been sister cities for over 30 years and this would be the perfect UK city to host the 2023 contest.”