Son of Ernest-Henri David (municipal councillor in the administration of Paris), he spent his childhood and early adolescence in Meknes, where his father was assigned as an engineering officer.
After graduating from the Sorbonne with a history degree, Jean-Paul David began his political career in 1935 as chief of staff to Paul Bénazet (in charge of the Senate Air Committee).
When World War II began, he was mobilised as an officer in the 7th Tank Battalion, where he distinguished himself by his courage and conduct.
The Rally of Republican Lefts was badly weakened by defections and in 1960 he joined with Pierre Marcilhacy to create from its remnants the European Liberal Party.
In 1950 he acquired fame by founding the anti-communist Paix et Liberté movement, which was highly active until 1955 and earned him a regular spot on French national radio.