Ion Raţiu was the son of Dr. Augustin Raţiu and Eugenia Turcu. He attended school in Turda and Cluj, and in 1938 he earned a law degree from Babeş-Bolyai University in Cluj. In 1940, Raţiu was named Counsellor at the Romanian Embassy in London. In September 1940, King Carol II fled Romania and this led to the formation of the National Legionary State. As a result, Ion Raţiu gave his demission from the Foreign Service, and requested political asylum in the United Kingdom. In 1943, Raţiu earned an economics degree from the University of Cambridge. He married Elisabeth, the daughter of colonel Guy Pilkington; the couple had two children, Indrei and Nicolae.
Raţiu was the founder of the "International Union of the Free Romanians" (Uniunea Mondială a Românilor Liberi) in 1984.
After he returned to Romania in January 1990, he helped to re-create the National Peasants' Party, serving as its vice-president. He unsuccessfully ran for president in the 1990 election; however, he was elected as deputy of the Romanian Chamber of Deputies in 1990, 1992 and again in 1996. In 1991, he re-founded the newspaper Cotidianul.