Simpson was born in Swansea, Wales. She graduated from the Chelsea School of Art in London in 1988 and earned an MFA from the Royal Academy of Art in London in 1993. In 1994 she was included in the seminal exhibition "Some Went Mad, Some Ran Away", curated by Damien Hirst, at the Serpentine Gallery, London. Simpson’s work was also part of the controversial "Sensation" exhibition of 1997.