Pierre-Étienne Flandin was a French conservative politician of the Third Republic, leader of the Democratic Republican Alliance, and Prime Minister of France from 8 November 1934 to 31 May 1935.
A military pilot during World War I, Flandin held a number of cabinet posts during the interwar period. He was Minister of Commerce, under the premiership of Frédéric François-Marsal, for just five days in 1924. He was Minister of Commerce and Industry in the premierships of André Tardieu in 1931 and 1932. Between those posts, he served under Pierre Laval as Finance Minister. He was Minister of Public Works in the cabinet of Gaston Doumergue in 1934. He became Prime Minister in November 1934, but his premiership lasted only until June 1935. However, a number of important pacts were negotiated during his term: the Franco–Italian Agreement, the Stresa Front and the Franco-Soviet Pact. Flandin was, at 45, the youngest prime minister in French history.
Flandin was the French Foreign Minister when Adolf Hitler reoccupied the Rhineland in 1936. Supporting appeasement during the Munich crisis hurt his career.