Methuselah's Children is a science fiction novel by American writer Robert A. Heinlein. Originally serialized in Astounding Science Fiction in the July, August, and September 1941 issues, it was expanded into a full-length novel in 1958. The novel is part of Heinlein's Future History series of stories. It introduces the Howard families, a fictional group of people who achieved long lifespans through selective breeding.

Robert Anson Heinlein was an American science fiction author, aeronautical engineer, and naval officer. Sometimes called the "dean of science fiction writers", he was among the first to emphasize scientific accuracy in his fiction, and was thus a pioneer of the subgenre of hard science fiction. His published works, both fiction and non-fiction, express admiration for competence and emphasize the value of critical thinking. His plots often posed provocative situations which challenged conventional social mores. His work continues to have an influence on the science-fiction genre, and on modern culture more generally.