Mo Hayder, born as Clare Damaris Bastin, also known by the pen names Theo Clare and Candy Davis, was a British author born on 2 January 1962 and passed away on 27 July 2021. Initially, she worked as an actress and model under the name Candy Davis and appeared as Miss Belfridge in the BBC sitcom Are You Being Served? She transitioned to writing novels under the name Mo Hayder, gaining fame for her gripping crime and thriller fiction.

Her novels have sold more than 6.5 million copies as of 2021. She won the prestigious Edgar Award in 2012. Some of her most notable works include Birdman and its sequel The Treatment. Her last book, The House of Sand, is set to be published in 2022.

Mo Hayder had a diverse career path, including roles as a barmaid, security guard, filmmaker, hostess in a Tokyo club, educational administrator, and teacher of English as a foreign language in Asia. She held an MA in film from The American University in Washington DC and an MA in creative writing from Bath Spa University, UK. She resided in Bath with her daughter, Lotte-Genevieve.