The Descendants star is attached to the movie based on David Grann's recent New Yorker article, reports Deadline.
The article, which was published on May 28, is about William Alexander Morgan, an American who helped Castro and the Cuban rebels overthrow former-President Fulgencio Batista.
Awarded the title of Comandante - a rare honour for a foreigner - he soon fell under suspicion of espionage for the US government and was sentenced to death by firing squad.
The actor will produce the film with his Smokehouse Pictures partner Grant Heslov.
Clooney was last seen in The Descendants and The Ides of March, the latter of which he also directed.
He is also in line to appear in Alfonso Cuaron's Gravity in 2013.