Polly Morgan was born in Barbury, Oxfordshire, England in 1980, and grew up in Cotswalds on her family farm, and mentions a lack of squeamishness about death as well as being comfortable with the practice of dealing with the corpses of animals. She moved to East London in 1998 and continues to live there today. As a result of a ruptured appendix when she was 31, she became infertile and has spoken out to try to end the public stigma against talking about out in-vitro fertilization. Morgan is a traditional libertarian.

Morgan did not plan an art career; she considered becoming an Actress after leaving school, but went to university instead. Morgan graduated from Queen Mary, University of London, in English Literature in 2002. During her studies, she worked in Shoreditch Electricity Showrooms, a bar popular with artists; after graduation, she continued to work there as manager. At 23 Morgan was living above the bar and working out of her apartment, "tinkering with taxidermy." Inspired to create work of her own she took a course with the professional taxidermist George Jamieson, of Cramond, in Edinburgh, during which her intuitive and personal response to the medium were obvious. Morgan's first pieces were commissioned by Bistrotheque, after which she was spotted by Banksy: A lovebird looking in a mirror; a Squirrel holding a belljar with a little fly perched inside on top of a sugar cube; a magpie with a jewel in its beak; and a couple of chicks standing on a miniature coffin'. In 2005, he invited her to show her work for Santa's Ghetto, an annual exhibition he organised near London's Oxford Street. Her next piece, a white rat curled up in a shallow champagne glass, was exhibited at Wolfe Lenkiewicz's Zoo Art Fair in 2005. That piece – 'Rest a Little on the Lap of Life' – was purchased before the show opened by Vanessa Branson. Morgan works from a Bethnal Green studio.