Harold Emery Moore, Jr. (July 7, 1917 – October 27, 1980) was an American botanist especially known for his work on the systematics of the palm family. He served as Director of the at Cornell University, and was appointed Liberty Hyde Bailey Professor of Botany in 1978. He was an important contributor to and was founding editor of the palm journal Principes (now Palms). He also edited and provided the foundation for the first edition of , a seminal work on palm taxonomy which was later completed by Natalie Uhl and John Dransfield.