The "bottom" ad campaign is London-focused and features advertising in the Evening Standard and Metro newspapers as well as on posters along the South Bank and postcards in bars, clubs and cinemas across the capital.
Shelter is using the campaign to raise awareness of what it is calling a "sit-in" event and exhibition taking place at the South Bank's Oxo Gallery from March 29 to April 2, featuring 5,000 pictures of celebrities including Davina McCall and Jarvis Cocker as well as members of the public, sitting in a red armchair.
At the exhibition, visitors will also get the chance to appear in the exhibition and have their photo taken in the red chair.
Adam Sampson, director of Shelter, said: "We hope these cheeky ads will encourage Londoners to come along to our photography exhibition at the Oxo Gallery."
This is the latest element of the charity's current Million Children campaign, which launched last year and revealed that more than 1m children in the UK are suffering from bad housing. The aim is to urge the government to build more social rented housing to alleviate the problem.
Other celebrities taking part in the exhibition, which is sponsored by social housing firm the Mears Group, are Ms Dynamite, Dame Kelly Holmes and Joseph Fiennes.
If you have an opinion on this or any other issue raised on Brand Republic, join the debate in the .