Linwood Vrooman Carter was an American author of science fiction and fantasy, as well as an editor, poet, and critic. He usually wrote as Lin Carter; known pseudonyms include H. P. Lowcraft (for an H. P. Lovecraft parody) and Grail Undwin. He is best known for his work in the 1970s as editor of the Ballantine Adult Fantasy series, which introduced readers to many overlooked classics of the fantasy genre.

Carter had a marked tendency toward self-promotion in his work, frequently citing his own writings in his nonfiction to illustrate points and almost always including at least one of his own pieces in the anthologies he edited. The most extreme instance is his novel Lankar of Callisto, which features Carter himself as the protagonist.

As an author, he was a member of the all-male literary banqueting club the Trap Door Spiders, which served as the basis of Isaac Asimov's fictional group of mystery solvers the Black Widowers.