Retinger was born in Kraków, Poland (at that time a part of Austria-Hungary), the youngest of four children. His father, Józef Stanisław Retinger, was the personal legal counsel and adviser to Count Władysław Zamoyski. When Józef H. Retinger's father died, Count Zamoyski took young Józef under his wing.
Financed by Count Zamoyski, Retinger attended the Sorbonne in 1906, and was the youngest person ever to earn a Ph.D. there, in 1908 at the age of twenty, before his move to England in 1911, where his closest friend was fellow Pole, Joseph Conrad. He would later write about Conrad in his book, Conrad and His Contemporaries (1943).
In 1917 Retinger travelled to Mexico, where he became an unofficial political adviser to union organizer Luis Morones and President Plutarco Elías Calles. Later, during World War II, he advised the Prime Minister of the Polish Government in Exile, General Władysław Sikorski. In 1944, aged 56, Retinger parachuted into occupied Poland with 2nd Lt. Tadeusz Chciuk-Celt, in Operation Salamander, to talk with leading political figures and deliver money to the Polish underground.
After the war, Retinger became a leading advocate of European unification and helped found both the European Movement and the Council of Europe. He was later to become Honorary Secretary General of the European Movement.
Retinger initiated the Bilderberg conferences (1954) and was their secretary until his death in 1960.