Prime Minister Boris Johnson met with Devon's charity campout star Max Woosey at Number 10 - before Action for Children's 'Boycott your Bed' event on 9 July.
The 11-year-old from Braunton in Devon, who has been camping in his garden since the start of the pandemic - was partly the inspiration for the charity's national sleepout event.
Action for Children hosted the virtual event on Friday evening, which connected everyone who had registered to take part.
Thousands of people camped out in unusual places across the UK to raise money for the charity - from camping under the stars to bunking down in the bathroom.
Max's involvement led him to meeting Boris Johnson and he got to pitch his tent in the Downing Street garden.
Prime Minister Boris Johnson said: "Max has done an absolutely stellar job of raising money for some very worthy causes by sleeping outside for over a year now.
"Max has inspired young people all over the country and I support his efforts to raise money for children who need it most."
Max's local MP, Selaine Saxby, added: "He has inspired so many children locally in North Devon to do something to help others."
Max reflected on his meeting with the Prime Minister: "It was so exciting to visit Number 10. Although I can't see myself ever sleeping in an actual bed again, I didn't expect my adventure to bring me to one of the most famous addresses in the world!
"I hope my camping efforts will inspire children and families across the country to support 'Boycott your Bed."
Action for Children protects and supports vulnerable children and young people. The charity ensures their voices are heard and campaigns to bring lasting improvements to their lives.
Melanie Armstrong, Action for Children's Chief Executive, said: "It's been a tough year, but Max and his trusty tent have been a shining light to children all over the UK. We want every child to have a safe and happy childhood. We would love families to follow Max's example and support Boycott your Bed, to help children who have been hit hardest by the pandemic."
The charity helps more than 387,000 children, teenagers, parents and carers every year.