Robert Albert Bloch was a prolific American writer. He was the son of Raphael "Ray" Bloch (1884, Chicago-1952, Chicago), a bank cashier, and his wife Stella Loeb (1880, Attica, Indiana-1944, Milwaukee, WI), a social worker, both of German-Jewish descent.

Bloch wrote hundreds of short stories and over twenty novels, usually crime fiction, science fiction, and, perhaps most influentially, horror fiction (Psycho). He was one of the youngest members of the Lovecraft Circle; Lovecraft was Bloch's mentor and one of the first to seriously encourage his talent.

He was a contributor to pulp magazines such as Weird Tales in his early career, and was also a prolific screenwriter. He was the recipient of the Hugo Award (for his story "That Hell-Bound Train"), the Bram Stoker Award, and the World Fantasy Award. He served a term as president of the Mystery Writers of America.

Robert Bloch was also a major contributor to science fiction fanzines and fandom in general. In the 1940s, he created the humorous character Lefty Feep in a story for Fantastic Adventures. He also worked for a time in local vaudeville, and tried to break into writing for nationally-known performers. He was a good friend of the science fiction writer Stanley G. Weinbaum. In the 1960's, he wrote 3 stories for Star Trek.