He speaks some French, but is not very fluent apparently. French was one of his 12 O level subjects (the UK exam for 16-year olds before GCSE) but that was a long time ago of course, and the O level didn't really require a very high level of fluency (though as he went to top public school Eton, we can assume that he would have been taught to a high standard). He has no other foreign languages as far as is generally known. No living ones, anyway - he would have studied Latin and probably Ancient Greek at Eton, but famously failed to translate the fairly well known Latin phrase 'Magna Carta' recently.
For A levels Cameron studied History, Economics with Politics and History of Art. At Oxford he studied politics, philosophy and economics, which has no requirement to study a foreign language.
All this forms a contrast to the Prime Minister's deputy, Nick Clegg, who speaks several languages including Spanish and Dutch.