William Robert Profitt, known as ‘Bill’, was head of the department of orthodontics at the University of North Carolina (UNC) at Chapel Hill, USA, and probably the most influential orthodontist of his generation. He grew up in Buies Creek, North Carolina, the son of teachers. His remarkable thirst for learning was evidenced by the fact that he taught himself to read at the age of three and subsequently skipped first grade. His mother, Edna, chair of the chemistry department at Campbell College, encouraged him to study science. He studied dentistry at UNC, gained a PhD in physiology at the Medical College of Virginia and completed his orthodontic residency program at the University of Washington. In 1965, he joined the faculty of the University of Kentucky and served as the first chairman of the orthodontic department. He then taught at the University of Florida for two years. In 1975 he joined the orthodontic faculty at UNC. He served as professor and later became chair of the department of orthodontics, a post he held for 26 years. He was still actively involved in teaching and lecturing at UNC and worldwide up until his death. In 1992, the UNC board of trustees appointed him a W R Kenan Distinguished Professor, considered to be one of the university’s most prestigious honours. An active researcher, Bill’s main interests were the aetiology of malocclusion and the effectiveness of combined orthodontic and orthognathic treatment. During his career, he published more than 200 scientific papers. He was one of the first orthodontists to adopt clinical trial methodology when his department carried out landmark studies into the early treatment of class II malocclusion. These provided models for the adoption of randomised controlled trial methodology in orthodontics throughout the world. Bill was also an approachable and effective educator. His textbook *Contemporary orthodontics* (Elsevier, Philadelphia, 2018), the sixth edition of which was published just before his death, was probably the most widely used book on orthodontic specialty programmes and is now available in 12 languages. Known simply as ‘Proffit’, nearly all orthodontists now own a copy. He also contributed chapters to 20 other books. Bill was a gifted and witty speaker whose lectures, delivered in his slow, southern drawl, were much in demand throughout the world for he had the ability of making the most complex subjects appear simple. Always keen to explore new teaching methods, in his later life he quickly adopted and pioneered online distance learning. A great anglophile, he was a frequent and welcome visitor to Britain and received an honorary FDS of the Royal College of Surgeons of England in 1990. His other many accolades included the American Dental Association Norton M Ross Award (1994), the American Board of Orthodontics Albert H Ketcham Award (2005) and the inaugural Lifetime Achievement Award in Orthodontic Research made by American Association of Orthodontics in 2017. Bill in his earlier days was a fit and fearsome tennis player. He was proud of his ability to grow disease-free English roses in the unfavourable North Carolina climate. The worldwide travel, which he greatly enjoyed with Sara, his wife of 65 years, was linked to his ambition of riding on all the world’s major railways. This he largely accomplished. Bill died on 30 September 2018. He was 81. He was survived by Sara and their three children, Lola, Ed and Glenn, eight grandchildren, and nine great-grandchildren. His influence on orthodontics has been immeasurable and all orthodontists throughout the world sadly miss him, many of whom contributed to the endowed chair created in his honour at UNC.