László Ferenczy (9 March 1898 – 31 May 1946)[1] was a lieutenant colonel in the Hungarian Royal Gendarmerie and member of its "central dejewification unit" during World War II and the Holocaust.

[2] Born in Felsővisó, Austria-Hungary, Ferenczy served from March 1940 to July 1942 with a unit that searched for Jews who had fled to Hungary from Slovakia.

After Nazi Germany's invasion of Hungary in March 1944, he was appointed—on 25 March—as liaison between the Hungarian Royal Gendarmerie and the German security police, which meant he worked closely with SS officer Adolf Eichmann.

[1][4] When Miklós Horthy, the Hungarian regent, ordered an end to the deportations in July, Ferenczy appeared to switch sides and in August made contact with the Budapest Aid and Rescue Committee, which was trying to make deals with Eichmann to halt the deportations.

[3] In October, when Ferenc Szálasi, head of the pro-Nazi Arrow Cross Party, became prime minister, Ferenczy was once again placed in charge of rounding up and deporting Jews.