French media seized on the error on Friday following the report.
Hollande told 25,000 supporters at a campaign rally in Le Bourget on Sunday that the "universal message" he wished to convey was best summed up by Shakespeare's words: "They failed because they did not start with a dream."
But The Daily Telegraph reported that Nicholas Shakespeare, a descendant of William's grandfather and the broadsheet's chief book reviewer, recognised the Socialist candidate's words as his own.
"I couldn't believe my eyes when I saw the French presidential candidate had quoted me," he said.
The words come from his 1989 novel "The Vision of Elena Silves" and were uttered by the novel's hero, Gabriel, a Maoist revolutionary who ends up a terrorist for the Peruvian guerrilla group, Shining Path.
"He is saying the last Marxist revolution of the Sixties had failed, but his is going to succeed and the idea is that they failed because they did not have a dream," Shakespeare told the Telegraph.
Hollande, leading in polls three months ahead of an election in which he is expected to face the incumbent Nicolas Sarkozy, unveiled a manifesto on Thursday focused on new spending and scrapping tax breaks.