The ad was created and produced by The Clinton Partnership, with media planning and buying handled by John Ayling Associates, and will air later this week.
The opening scenes feature Clunes addressing the audience in front of a dark enclosing wall, to depict the captivity of wild animals in Africa.
The ad was directed by Jeremy Hibert and features Clunes, a long-term supporter of the charity.
Simon Clinton, owner of the Clinton Partnership, said: "We're proud to be supporting the Born Free Foundation.
"It comprises of a great, passionate team who are focused on keeping animals in the wild across the globe, a charity we're delighted to be working with."
Follow Daniel Farey-Jones on Twitter @danfareyjones