Robert IV de La Marck (15 January 1512 – 4 November 1556) was Duke of Bouillon, Seigneur of Sedan and a Marshal of France.

He rose to prominence during the reign of Henri II of France as a favourite of both the king and his mistress Diane de Poitiers.

[2] In the early years of Henri's reign, he found himself a regular member of the conseil des affairs which set the direction of royal policy.

[3] Bouillon was a keen advocate for the resumption of the Italian Wars, hoping to regain his territory and Diane de Poitiers championed this cause with him.

[9] Bouillon's wife had travelled to Brussels to plead for a more affordable ransom, however this was only agreed to due to his poor health, which meant that several days after release he died.