Sir Ian Bruce Hassall KNZM (10 August 1941 – 14 June 2021) was a New Zealand paediatrician and children's advocate. He was New Zealand's first Commissioner for Children from 1989 to 1994. His career entailed working for children and their families as clinician, strategist, researcher and advocate. He was awarded the Aldo Farina Award by UNICEF in 2010 for his dedication to improving child welfare.