Neal Town Stephenson (born October 31, 1959) is an American writer known for his works of speculative fiction. His novels have been categorized as science fiction, historical fiction, cyberpunk, and baroque.

Stephenson's work explores mathematics, cryptography, linguistics, philosophy, currency, and the history of science. He also writes nonfiction articles about technology in publications such as Wired. He has written novels with his uncle, George Jewsbury ("J. Frederick George"), under the collective pseudonym Stephen Bury.

Stephenson has worked part-time as an advisor for Blue Origin, a company (founded by Jeff Bezos) developing a spacecraft and a space launch system, and also co-founded the Subutai Corporation, whose first offering is the interactive fiction project The Mongoliad. He was Magic Leap's chief futurist from 2014 to 2020.

Born on October 31, 1959, in Fort Meade, Maryland, Stephenson came from a family of engineers and scientists; his father is a professor of electrical engineering and his paternal grandfather was a physics professor. His mother worked in a biochemistry laboratory and her father was a biochemistry professor. Stephenson's family moved to Champaign-Urbana, Illinois, in 1960, and to Ames, Iowa, in 1966. He graduated from Ames High School in 1977.

Stephenson studied at Boston University, first specializing in physics, then switching to geography after he found that it would allow him to spend more time on the university mainframe. He graduated in 1981 with a B.A. in geography and a minor in physics.

Since 1984, Stephenson has lived mostly in the Pacific Northwest and as of 2012 lived in Seattle with his family.

Stephenson's first novel, The Big U, published in 1984, is a satirical take on life at American Megaversity, a vast, bland, and alienating research university beset by chaotic riots. His next novel, Zodiac (1988), is a thriller following a radical environmentalist in his struggle against corporate polluters. Neither novel attracted much critical attention on first publication, but both showcased concerns that Stephenson developed in his later work.

Stephenson's breakthrough came in 1992 with Snow Crash, a cyberpunk or postcyberpunk novel fusing memetics, computer viruses, and other high-tech themes with Sumerian mythology, along with a sociological extrapolation of extreme laissez-faire capitalism and collectivism. Mike Godwin described Stephenson at this time as "a slight, unassuming grad-student type whose soft-spoken demeanor gave no obvious indication that he had written the manic apotheosis of cyberpunk science fiction." In 1994, Stephenson and his uncle, J. Frederick George, published a political thriller, Interface, under the pen name "Stephen Bury"; they followed this in 1996 with The Cobweb.