Ligeti was born in DicsŠ‘szentmárton, which was renamed TârnÄƒveni in 1945, in Transylvania to a Hungarian Jewish family. Ligeti recalls that his first exposure to languages other than Hungarian came one day while listening to a conversation among the Romanian-speaking town police. Before that he hadn't known that other languages existed. He moved to Cluj (Kolozsvár) with his family when he was 6, and he was not to return to the town of his birth until the 1990s.
Ligeti received his initial musical training at the conservatory in Cluj, and during the summers privately with Pál Kadosa in Budapest. In 1940, Northern Transylvania was occupied by Hungary following the Second Vienna Award. In 1944, Ligeti's education was interrupted when he was sent to a forced labor brigade by the Horthy regime. His brother, age 16, was deported to the Mauthausen concentration camp, and both of his parents were sent to Auschwitz. His mother was the only other survivor of his immediate family.
Following the war, Ligeti returned to his studies in Budapest, Hungary, graduating in 1949 from the Franz Liszt Academy of Music. He studied under Pál Kadosa, Ferenc Farkas, Zoltán Kodály and Sándor Veress, and regularly attended lectures by Lajos Bárdos. He went on to do ethnomusicological research into the Hungarian folk music of Transylvania, but after a year returned to his old school in Budapest, this time as a teacher of harmony, counterpoint and musical analysis. However, communications between Hungary and the West by then had become difficult due to the restrictions of the communist government, and Ligeti and other artists were effectively cut off from recent developments outside the Soviet bloc.