Charles II de Croÿ (July 31, 1522 – Quiévrain, June 24, 1551) was Seigneur de Croÿ, 2nd Duke of Aarschot, 3rd Prince of Chimay and 3rd Count of Beaumont.
He was the eldest son of Philippe II de Croÿ, Duke of Aarschot, and Anne de Croÿ, Princess of Chimay.
He inherited after his mother's death in 1539 the Principality of Chimay and after his father's death in 1549 the Duchy of Aarschot, thus uniting for the first time the two great titles of the House of Croÿ .
He married in 1541 Louise de Lorraine (1521–1542), daughter of Claude, Duke of Guise and Antoinette de Bourbon, and younger sister of Mary of Guise, who was married to King James V of Scotland. In other words, Mary, Queen of Scots was his niece.
After the early death of Louise, he remarried in 1549 with Antoinette of Burgundy (1529–1588), sister of Maximilian II of Burgundy, who was married to his sister Louise de Croÿ (1524–1585).
Charles de Croÿ was murdered in 1551 in Quiévrain. Because he had no children, all his titles and possessions went to his younger brother Philippe III de Croÿ. His widow later remarried Jacques d’Anneux, Seigneur d‘Aubencourt.