Zacharias "Zak" Kostopoulos (Greek: Ζαχαρίας «Ζακ» Κωστόπουλος; 22 August 1985 – 21 September 2018) was a Greek-American activist, defending the rights of LGBT people, HIV-positive people, sex workers and refugees. He was also a drag performer under the name Zackie Oh.[1][2] He was killed at the center of Athens.