Hunt has been accused by opposition Labour of breaching the ministerial code of conduct in the failed BSkyB deal in 2010.
Speaking to the BBC, Cameron Hunt had "acted wisely" and given "a good account of himself" on the issue to the Leveson Inquiry into media ethics and to the British Parliament.
"The advice I was given was that what mattered was not what Jeremy Hunt had said publicly or privately but how he was going to conduct himself during the bid," he said.
"That's how I think we should judge him: did he adjudicate this bid wisely and fairly?
"And he did. He took legal advice at every stage, and he followed that legal advice and he did many things that were not in the interests of the Murdochs or BSkyB and that side of things," the British Prime Minister said.
Cameron said he sought advice from the cabinet secretary before deciding to give responsibility for the bid to Hunt.
Hunt took on the role after Business Secretary Vince Cable said he had "declared war" on Rupert Murdoch.
Before taking responsibility for the bid Hunt had publicly expressed his support for it. BSkyB is a British satellite broadcasting, broadband and telephony services company.
Labour want Hunt to be investigated for breaching the ministerial code, following the publication of correspondence between Hunt's special adviser, Adam Smith, who later resigned and News Corp lobbyist Fred Michel.
Hunt, Michel and Smith have all appeared before the Leveson Inquiry.
Shortly after Hunt finished giving evidence to the inquiry, Downing Street confirmed the prime minister would not refer the case to Sir Alex Allen, his adviser on the ministerial code, the BBC reported.
Murdoch eventually withdrew the multi-billion BSkyB bid in the face of public revulsion and anger over allegations of phone-hacking at his News of the World tabloid.
