Paul Louis François Spaak (5 July 1871 – 8 May 1936) was a Belgian lawyer, poet, literary historian, and playwright.

Born in Ixelles, Spaak graduated in law at the Université Libre de Bruxelles in 1894.

The couple had four children, of whom Paul-Henri Spaak, later Belgian Prime Minister like his uncle Paul-Emile Janson, was the most famous.

From 1920 until his death, Paul Spaak was co-director of the Théâtre Royal de la Monnaie.

He shared this position with Maurice Corneil de Thoran and Jean Van Glabbeke.