No. Like all past Assassin’s Creed games there is no option to change the difficulty to hard or easy. There is a single difficulty that you have to use. There are several features in the game such as ‘eagle vision’. These features will make the game easier by highlighting targets and enemies. If you play the game and avoid using this as much as possible it will make the game more difficult.
Home Is There a Difficulty Selection In Assassin's Creed IV?