The son of Claude Lamoral, prince de Ligne, head of a family long established in Hainaut and in the Holy Roman Empire, de Ligne married Marie-Françoise de Liechtenstein in 1755. After serving with distinction for Austria in the Seven Years' War (1756–63), he became a trusted adviser of the Holy Roman emperor Joseph II, who sent him on missions to Catherine the Great (Catherine II) of Russia in 1780 and 1786. He traveled with Catherine in 1787, and in 1788–89 he fought for Russia and Austria in the Russo-Turkish War of 1787–92.

De Ligne's memoirs and letters reflect his experiences as a favourite at the leading European courts and salons until his exile following the Belgian rebellion of 1789. His works include Mélanges militaires, littéraires et sentimentaires, 34 vol. (1795–1811; “Miscellaneous Military, Literary, and Sentimental Memoirs”), Fragments de l'histoire de ma vie (1927; “Fragments of the History of My Life”), and Letters and Memoirs of the Prince de Ligne (translated by Leigh Ashton, 1927).