Jean Rey (French: [ʒɑ̃ ʁɛ]; 15 July 1902 – 19 May 1983) was a Belgian Liberal politician who served as the second president of the European Commission from 1967 to 1970.

In the wake of World War II, he was one of the most vocal opponents of the "policy of independence" (neutrality) supported by successive Belgian governments and King Leopold III.

He was captured by the Germans and spent the rest of the conflict as a prisoner of war, being interned in Oflag XD near Fischbeck, where he was a member of the clandestine Masonic Lodge L'Obstinée.

As early as 1947 he promoted, together with five other members of Parliament (among whom Julien Lahaut), a bill on the organisation of a federal state.

If passed, the new Constitution would have transformed Belgium into a Confederation consisting of two States, Flanders and Wallonia, and the federal region of Brussels.

Finally, in 1970, the last year of this mandate, Rey won the European governments' support for his proposal to give the Community "own resources".