Gene Brewer (born Eugene N. Brewer, 4 July 1937) is an American writer, was born at in Muncie, Indiana.

He was educated at DePauw University and University of Wisconsin–Madison, and he studied DNA replication and cell division before becoming a novelist.

Brewer is known as the author of the K-PAX book series, about a man who claims to be a visiting extraterrestrial from a planet called K-PAX: K-PAX (1995), On a Beam of Light (2001), K-PAX III: The Worlds of Prot (2002), K-PAX IV: A New Visitor from the Constellation Lyra (2007), K-PAX V: The Coming of the Bullocks (2014) and Prot's Report, a brief natural history of the Earth, which appears in K-PAX: The Trilogy, an omnibus edition of the first three K-PAX books.

The first book in the series was made into a Universal Pictures film in 2001; it stars Kevin Spacey and Jeff Bridges.

Brewer currently lives in New York City and Vermont, with his wife. He is a vegan.

Psychiatrist Gene Brewer doesn't have a diagnosis for the mysterious new patient who calls himself "prot" (rhymes with goat). But this strange and likeable man cannot be--as he claims--from the planet K-PAX.

Or can he? Prot knows facts about space that are confounding the experts. He is soon revealing Dr. Brewer's own deepest pains and most sublime longings. And his tales of K-PAX have other patients competing to go along with him when he heads "home". Now the doctor is racing the clock to find prot's true identity before he losses a man whose "madness" might just save them all. . .

Published in a dozens countries with movie rights sold to the producer of Field of Dreams, K-PAX has touched the hearts and expanded the horizons of readers around the world. It promises to join Robert Heinlein's classic Stranger in a Strange Land as a moving, thought-provoking masterpiece of modern-day fiction.