The ads, which are appearing in the national press from today, show Davis, who played receptionist Dawn Tisley in BBC comedy 'The Office', posing nude clutching a teddy bear under the strapline "Bare skin, not bear skin".
The campaign is part of Peta's aim to stop Canadian black bear fur being used by the Queen's Guards for the making of ceremonial caps, and follows last year's naked Sadie Frost ads which raised awareness of cruelty in using animal fur.
Peta said it can take an entire bear hide to make one Guard's headpiece, and that animals can be shot "several times" before being killed. The organisation said the killing of mother bears often left orphaned cubs to starve to death.
Davis said: "So much money is spent, and so much cruelty is spent on what at the end of the day is a hat -- and that is it."
Davis joins a number of actors and models who had fronted its anti-fur campaigns, including Roger Moore, Amanda Holden, Twiggy and Pamela Anderson.
Peta escaped an ad ban in January for posters featuring the strapline "Feeding kids meat is child abuse."