Paul-Armand Challemel-Lacour (19 May 1827 – 26 October 1896) was a French statesman.
He was born in Avranches in the Manche département of northwestern France. After passing through the École Normale Supérieure he became professor of philosophy successively at Pau and at Limoges. The coup d'état of 1851 by Napoleon III caused his expulsion from France for his republican opinions. He travelled on the continent, gave conferences in Belgium and in 1856 settled down as professor of French literature at the Federal Polytechnic Institute Zurich, today the ETH Zurich. The amnesty of 1859 enabled him to return to France, but a projected course of lectures on history and art was immediately suppressed. He now supported himself by his pen, and became a regular contributor to the reviews.
On the fall of the Second French Empire in September 1870 the government of national defence appointed him prefect of the Rhône département, in which capacity he had to suppress the Communist rising at Lyon. Resigning his post on the 5 February 1871, he was in January 1872 elected to the National Assembly, and in 1876 to the Senate. He sat at first on the Extreme Left; but his philosophic and critical temperament was not in harmony with the recklessness of French radicalism, and his attitude towards political questions underwent a steady modification, till the close of his life saw him the foremost representative of moderate republicanism.