François Hercule, Duke of Anjou and Alençon, (March 18, 1555 - June 19, 1584) was the youngest son of Henry II of France and Catherine de' Medici.

In 1574, following the death of his brother Charles IX of France and the accession of his other brother Henry III of France, he became heir to the throne. In 1576 he was made Duke of Anjou in succession to his brother Henry.

In 1576 he negotiated the Peace of Beaulieu during the French Wars of Religion. In 1579 he was invited by William the Silent to become hereditary sovereign to the United Provinces. On 29 September 1580, the Dutch Staten Generaal (with the exception of Zeeland and Holland) signed the Treaty of Plessis-les-Tours with the Duke, who would assume the title "Protector of the Liberty of the Netherlands" and become the sovereign. At the same time, in 1581, arrangements began to be made for his marriage to Elizabeth I of England. His abortive visit to Elizabeth delayed his arrival in the Nethrlands; he did not arrive until 10 February 1582, when he was officially welcomed by William in Flushing.

Anjou was not very popular with the Dutch, who continued to see the Catholic French as enemies; the provinces of Zeeland and Holland refused to recognise him as their sovereign, and William was widely critised for his "French politics". When Anjou's French troops arrived in late 1582, William's plan seemed to pay off, as even the Duke of Parma feared that the Dutch would now gain the upper hand.

However, the Duke of Anjou himself was dissatisfied with his limited power, and decided to take the city of Antwerp by force on January 18, 1583. The citizens defended their city in what is known as the "French Fury". The position of Anjou after this attack became impossible to hold, and he eventually left the country in June. His leave also discredited William, who nevertheless maintained his support for Anjou.

Anjou's premature death meant that the Huguenot Henry of Navarre became heir-presumptive, thus leading to an escalation in the Wars of Religion.