William ("Bill") E. Pelham Jr. was a renowned clinical child psychologist who specialized in the assessment and treatment of children with attention-deficit/hyperactivity disorder (ADHD). Bill was born in 1948 in Atlanta, Georgia, to William E. Pelham Sr. and Kittie Copeland Kay, the eldest of four brothers. Bill is most well-known for the development, study, and advocacy of psychosocial treatments for children with ADHD. While at Florida State University in the 1980s, he developed a comprehensive summer treatment program designed to improve family and classroom functioning, strengthen peer relationships, and boost academic achievement. Bill built the case for the behavioral treatment of ADHD over nearly 50 years of programmatic research. Bill was a leader in the field of clinical child psychology. Bill passed away on October 21, 2023, after a brief illness. He is survived by his wife of 33 years Maureen, son William E. Pelham III, and daughter Caroline. His legacy will live on in their work to support children with ADHD and their families. (PsycInfo Database Record (c) 2024 APA, all rights reserved).