Graham Frederick Young (7 September 1947 – 1 August 1990), also known as the Teacup Poisoner and the St Albans Poisoner, was an English serial killer who killed his victims via poison.

Obsessed with poisons from an early age, Young started poisoning the food and drink of relatives and school friends. He was caught when his teacher became suspicious and contacted the police. Young pleaded guilty to three non-fatal poisonings and, at age 14, was detained at Broadmoor Hospital. Young later took responsibility for the death of his stepmother, though this has not been proven.

After being released in 1971, Young got a job in a factory in Bovingdon, Hertfordshire, where he began poisoning his work colleagues, resulting in two fatalities and several critical illnesses. Young was convicted on two counts of murder and two counts of attempted murder in 1972. He served most of his life sentence at HM Prison Parkhurst, where he died of a heart attack in 1990.

The Young case made headlines in the United Kingdom and led to a public debate over the release of mentally ill offenders. Within hours of his conviction, the British government announced two inquiries into the issues it raised. The Butler Committee led to widespread reforms in mental health services, while the passage of the 1972 Poisons Act put severe restrictions on the purchase of deadly poisons. Young's life story inspired the 1995 film The Young Poisoner's Handbook.