William Least Heat-Moon, born William Lewis Trogdon, is an American travel writer and historian of English, Irish, and Osage ancestry. He is renowned for his bestselling trilogy of topographical U.S. travel writing. His pen name originated from his father's words: "I call myself Heat Moon, your elder brother is Little Heat Moon. You, coming last, therefore, are Least."

He was born on August 27, 1939, in Kansas City, Missouri. Heat-Moon pursued his education at the University of Missouri, earning bachelor's, master's, and Ph.D. degrees in English, along with a bachelor's degree in photojournalism. Additionally, he served as a professor of English at the university.

William Least Heat-Moon is the author of several books that chronicle unusual journeys through the United States, including cross-country trips by boat in River-Horse (1999) and his best-known work Blue Highways (1982), which documents his journey in a 1975 Ford Econoline van.