Mary Ann Lamb (3 December 1764 – 20 May 1847), was an English writer, the sister and collaborator of Charles Lamb. She is best known today for her collaboration with Charles on the collection Tales from Shakespeare. Mary suffered from mental illness, and in 1796 she stabbed her mother to death during a mental breakdown. She was confined to mental facilities off and on for most of her life. She and Charles presided over a literary circle in London that included the poets William Wordsworth and Samuel Taylor Coleridge, among others.