Győző Istóczy (7 November 1842, Szentkereszt – 9 January 1915, Budapest) was a Hungarian nationalist politician and lawyer in the second half of the 19th century.

He was born in Szentkereszt (today: Táplánszentkereszt, Vas County) on 7 November 1842.

In 1880 he founded the Alliance of Non-Jews and edited the anti-Semitic journal Tizenkét röpirat ("Twelve pamphlets").

During the Tiszaeszlár blood libel (murder of the girl Eszter Solymosi) in 1882, Géza Ónody, the representative of Tiszaeszlár in the Hungarian Parliament, and Istóczy proposed the expulsion of the Jews in the House of Representatives, and excited the public against the local Jews, resulting in a number of violent acts and pogroms.

Despite the victim Eszter Solymosi having probably been a victim of a sexual aggression (pedophilia), they spread the charge that the Jews killed the girl in order to use her blood at the approaching Passover (April 4).