A list of events in 1991 related to serial killers.
January[]
- 9 — Aileen Wuornos is apprehended.
February[]
- 19 — Dámaso Rodríguez Martín died.
March[]
- 3 — Cleophus Prince Jr. is apprehended.
- 17 — John Fautenberry is apprehended.
- 22 — Charles Albright is apprehended.
- 27 — Eric Napoletano is apprehended.
April[]
- 3 — Kwon Soo-sang is murdered by Lee Choon-jae.
- 3 — Becky Phillips is murdered by Beverley Allitt.
- 4 — Lee Choon-jae's victim, Kwon Soo-sang, is found.
- 5 — Talita Bremer is murdered by Beate Schmidt.
- 7 — Errol Lindsey is murdered by Jeffrey Dahmer.
- 22 — Tadeusz Kwaśniak is apprehended.
- 22 — Claire Peck is murdered by Beverley Allitt.
- 23 — Mario Normore is born.
- 27 — The "Bowraville Killers"'s 2nd known victim, Evelyn Greenup, is found.
- 28 — Phillip Jablonski is apprehended.
May[]
- 18 — Eugene Broxton is apprehended.
- 24 — Tony Hughes is murdered by Jeffrey Dahmer.
- 27 — Konerak Sinthasomphone is murdered by Jeffrey Dahmer.
- 31 — Joseph Akin is apprehended.
June[]
- 1 — Jack Jones's victim, Lori Barrett, is found.
- ? — Robert Lee Walden is apprehended.
July[]
- 1 — Joachim Kroll died.
- 6 — Muthukutty Chandran died.
- 22 — Jeffrey Dahmer is apprehended.
- 24 — Tadeusz Kwaśniak died.
- 26 — Lester Ford is apprehended.
August[]
- 1 — Beate Schmidt is apprehended.
- 5 — Donald Evans is apprehended.
- 5 — Andrei Sibiryakov died.
- 28 — Sergey Tsukanov is apprehended (first arrest).
September[]
- 6 — Donald Gaskins died.
- 17 — Lutz Reinstrom is apprehended.
- 26 — Sonia Gaona Yaguno is born.
October[]
- 21 — Rudolfo Infante and Anna Villeda are apprehended.
November[]
December[]
- 5 — Richard Speck died.
- 18 — Marcelo Costa de Andrade is apprehended.
- 20 — Timofey Podshivalov is born.
- ? — Joe Fischer died.
- ? — Isabel Padilla Maiquez is apprehended.
Unknown[]
- ? — Beverley Allitt is apprehended.
- ? — Apollonia Angiulli is apprehended.
- ? — Shiquan Bellamy is born.
- ? — Christopher Below is apprehended.
- ? — Adam Beniquez is apprehended.
- ? — Dmitry Chernov is born.
- ? — Robert Foley is apprehended.
- ? — Roman Horáček is apprehended.
- ? — Hayato Imai is born.
- ? — Ronnie Johns is apprehended.
- ? — Michael Magliolo is apprehended.
- ? — Alfred Lee Robinson is apprehended.
- ? — Pankaj Sharma is born.
- ? — Jozef Slovák is apprehended.
- ? — Oleg Snegov is apprehended.
- ? — Michael St. Clair is apprehended.
- ? — Ioan Sârca died.
- ? — Juan Carlos Villa is born.
- ? — Willie Williams is apprehended.