| alias = {{unbulleted list | The Killer Clown<ref>''Twentieth Century Murder'' {{ISBN|978-1-858-91390-2}} p. 90</ref> | Pogo the Clown<ref>{{cite web |url=https://www.biography.com/people/john-wayne-gacy-10367544 |title=John Wayne Gacy Biography |author=<!--Not stated--> |date=February 11, 2019 |orig-year=April 2, 2014 |website=Biography.Com WebSite |publisher=A&E Television Networks |access-date=April 5, 2019}}</ref>}}
| image = John Wayne Gacy.jpg
| caption = John Wayne Gacy in May 1978
| birth_name = John Wayne Gacy
| birth_date = {{Birth date|1942|03|17}}
| birth_place = [[Chicago]], [[Illinois]], US
| death_date = {{Death date and age|1994|05|10|1942|03|17}}
| death_place = [[Stateville Correctional Center]], [[Crest Hill, Illinois]], US
| cause = [[Lethal injection|Execution by lethal injection]]
| victims = 33+
| parents = John Stanley Gacy<br /> Marion Elaine Robinson
| party = [[Democratic Party (United States)|Democratic]]{{sfn|Linedecker|1980|p=70}}
| height = 5 ft 9 in{{sfn|Sullivan|Maiken|2000|p=5}}
| weight = 230 lb<ref>''Serial Killers''. p. 49.</ref>
| country = United States
| states = Illinois
| beginyear = January 3, 1972
| endyear = December 11, 1978
| apprehended = December 21, 1978
| conviction = {{unbulleted list|1 count of [[sodomy]]|33 counts of [[murder]]|1 count of [[sexual assault]]|1 count of [[Child abuse|indecent liberties with a child]]}} (March 12, 1980)
'''John Wayne Gacy''' (March 17, 1942 – May 10, 1994) was an [[Americans|American]] [[serial killer]] and [[rapist]] who [[sexual assault|sexually assaulted]], [[torture]]d and murdered at least 33 teenage boys and young men between 1972 and 1978 in [[Cook County, Illinois|Cook County]], [[Illinois]] (a part of [[Chicago metropolitan area|metropolitan Chicago]]).