Hilary Cass

Hilary Dawn Cass, Baroness Cass, OBE, FRCP, FRCPCH (born 19 February 1958), is a British paediatrician. She was the chair of the British Academy of Childhood Disability, established the Rett Clinic for children with Rett syndrome, and has worked to develop palliative care for children. She led the Cass Review of gender identity services in England, which was completed in 2024. Cass was appointed to the House of Lords as a crossbench life peer in the same year.

Cass is a former president of the Royal College of Paediatrics and Child Health, and a honorary physician in paediatric disability at the Evelina Hospital, part of Guy's and St Thomas' NHS Foundation Trust. Prior to Cass's appointment at the Evelina Hospital, she had been consultant at Great Ormond Street Hospital for 15 years. Her research and interests have included autistic spectrum disorders, cognitive impairment due to epilepsy, children with visual loss, and care of children with multiple disabilities.