Born in Devon, Mary Allen has lived in Cornwall from a very young age. The coastal waters around Gwithian and St Ives were a formative influence on her but it was only after retirement that she had the opportunity to devote more time to her painting. Her first solo exhibition was held in 2007.

Her marine studies are painted from her studio at St Hilary Churchtown, near Penzance. She is a regular exhibitor at the Harbour Gallery in Portscatho.