The politician made reference to The Smiths' single 'Heaven Know I'm Miserable Now' in a BBC montage for The One Show before saying sorry to Morrissey for liking him.
"I'm sure when Morrissey finds that he's getting an endorsement from the leader of the Conservative Party, he will think 'Heaven knows I'm miserable now,'" he said.
"But I'm a big fan, I'm afraid. Sorry about that."
The singer has previously been critical of The Conservatives and included a song called 'Margaret On The Guillotine' on his first solo album Viva Hate in reference to the party's former leader Margaret Thatcher.
Responding to Cameron's admission, the star replied: "It's difficult to make a comment because you might hurt people's feelings."
Morrissey's new album Years Of Refusal is out now.