Alexandre Du Sommerard (1779, Bar-sur-Aube - 19 August 1842, Paris) was a French archaeologist and art collector.
He volunteered for the army at 14 and took part in the French Revolutionary Wars. Returning to civil life, he became attached to the Cour des comptes, at first as a référendaire, then as a conseiller-maître, spending all his leisure time and most of his modest fortune on collecting, classifying and publishing a collection of medieval and Renaissance art objects.
Each day, his cabinet of furniture, vases and utensils of all kinds which he saved from their destroyers, since for a long while he was almost the only person in Paris collecting these curiosities that were later so much studied. Little by little he gained imitators and, always ready to reply to questions of taste and even enquiries from the indiscrete curious, Du Sommerard welcomed people to see his collection and gave lessons in practical archaeology.
The hôtel de Cluny, a Gothic palace built in the late 15th century by Jacques d'Amboise and the only surviving medieval palace in Paris, owes its survival to Du Sommerard. He took it over as a home and as a place to house his collection. On his death the Musée d’antiquités nationales that he created was acquired by the French state and rue des Mathurins was renamed rue du Sommerard in his honour.