Kingsley Green is a mental health and learning disabiity site located in Hertfordshire, England, just southeast of the village of London Colney. Located on Harper Lane, Shenley, Herts WD7 9HQ, it was known as Harperbury Hospital for 61 years and has been a fixture of the area's mental health scene since 1928. It had two sister institutions, Shenley Hospital and Napsbury Hospital, within a few miles of its location.