Ernő Gerő (1898 - 1980) was a Hungarian Communist leader in the period after World War II and briefly leader of Hungary in 1956.

Gerő was born in Hungary. He was involved in Comintern - the international association of communists - in France, and fought in the Spanish Civil War.

In the November 1945 elections, Hungary, the Hungarian Communist Party, under Gerő and Mátyás Rákosi got only 17% of the vote, compared to 57% for the Smallholders Party . However, the Soviet Commander in Hungary, Marshal Kliment Voroshilov installed a coalition government with Communists in key posts. The Communists took control in 1947, with Rákosi as Prime Minister (and effective head of state). Rákosi's authority was undermined by Khrushchev's secret speech denouncing Stalinism, and he left office on 18 July 1956, though he was able to designate Gerő as his successor.

Gerő was forced to resign during the events of the Hungarian Uprising. He was replaced by János Kádár and fled to the Soviet Union.