The final series of the ITV medical drama set in the Cornish village of Portwenn will air this year and be followed by a Christmas special, after nine prior series since 2004.
Clunes told Radio Times magazine — reported via The Sun — that fan uproar over potential cancellation didn't play into the decision to end the show.
"We didn’t make [fans] part of any decision-making process at any other point, so mind your own business," said the 60-year-old star.
Watch: Doc Martin cast film final scene in Port Isaac
He added: "One of my wife’s riding teachers says never let the horse make the decision, horses make terrible decisions. So maybe never let a viewer make a decision."
Doc Martin featured Clunes as former vascular surgeon Dr Martin Ellingham, who decides to become a GP in a Cornish village when a fear of blood forces him to ditch his career in London.
Speaking earlier this year when the show's cancellation was announced, Clunes thanked the "beautiful county" of Cornwall for giving the show a home.
"The people of Cornwall, and Port Isaac in particular, have always been so helpful to us when we are making the series," said Clunes.
He added: "We have some great story lines for the new series, and for the Christmas special, which I hope Doc Martin fans will love.
"I shall miss Cornwall, and all the lovely people we have worked with. But it is the right time to say farewell to the Doc, and Portwenn."
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Since its debut in 2004, Doc Martin has aired all over the world and been remade in countries including France, Russia and Greece.
The 10th and final series of Doc Martin will begin airing on 7 September, to be followed by the Christmas special and a documentary examining the show's legacy.
Watch: Phillip Schofield after Martin Clunes swears on This Morning