Andy Weir (; born June 16, 1972) is an American novelist. His 2011 novel The Martian was adapted into the 2015 film of the same name directed by Ridley Scott. He received the John W. Campbell Award for Best New Writer in 2016. His 2021 novel Project Hail Mary was a finalist for the 2022 Hugo Award for Best Novel, and has also been adapted into a film, released in March 2026.
Andy Weir was born in Davis, California, and grew up in Livermore, California. His father, John Weir, was a physicist at Lawrence Livermore National Laboratory, and his mother was an electrical engineer. He was an only child, and his parents divorced when he was 8. Weir grew up reading classic science fiction such as the works of Arthur C. Clarke and Isaac Asimov. He attended Livermore High School. At the age of 15, he began working as a computer programmer for Sandia.
After high school, Weir studied computer science at the University of California, San Diego, although he did not graduate.
Weir worked as a programmer for several software companies, including AOL, Palm, MobileIron, and Blizzard, where he worked on the video game '. Weir was fired from Blizzard in 1995 for poor performance. He later complained that the company's early structure did not provide adequate job training.
Weir began writing science fiction in his twenties and published work on his website for years. He authored a humor web comic, Casey and Andy, featuring fictionalized "mad scientist" versions of himself and his friends (such as writer Jennifer Brozek) from 2001 to 2008. He also briefly worked on another comic, Cheshire Crossing (bridging Alice in Wonderland, Peter Pan, The Wizard of Oz, and Mary Poppins), from 2006 to 2008. The attention these gained him has been attributed as later helping launch his writing career, following his failure to publish his first novel attempt, Theft of Pride. His first work to gain significant attention was "The Egg", a 2009 short story that has been adapted into a number of YouTube videos and a one-act play, and is the overarching concept of 2017's Everybody, the third album by American rapper Logic.
Weir wrote his first published novel, The Martian, to be as scientifically accurate as possible, doing extensive research into orbital mechanics, conditions on the planet Mars, the history of human spaceflight, and botany. Originally published as a free serial on his website, some readers requested he make it available on Amazon Kindle. First sold for 99 cents, the novel made it to the Kindle bestsellers list. Weir was then approached by a literary agent and sold the rights to Crown Publishing Group. The print version (slightly edited from the original) debuted at No. 12 on The New York Times bestseller list in 2014. The Wall Street Journal called it "the best pure sci-fi novel in years". It was adapted into a film in 2015 starring Matt Damon and Jessica Chastain.
In 2015, Weir announced he was working on his second novel, provisionally titled Zhek, which he described as "a more traditional sci-fi novel with aliens, telepathy, faster-than-light travel, etc." A fan-fiction story written by Weir, "Lacero", was published in the 2016 edition of Ready Player One, making it canonical to the book's fictional universe. The work functions as a prequel to the main novel, focusing on the novel's antagonist Nolan Sorrento / IOI-655321. Also in 2016, Weir released The Principles of Uncertainty, a collection of short stories, on the website/app Tapas.
After announcing that the Zhek project had been "back-burnered", Weir moved on to another hard sci-fi novel, Artemis, set on the Moon in the 2080sâÂÂ2090s. The thriller, published in 2017, follows Jazz, a 26-year-old woman constrained by her small town, which is also the only city on the Moon. In May 2017, 20th Century Fox and New Regency acquired the film rights to the book. On September 26, 2017, it was announced that Phil Lord and Christopher Miller had signed on to develop and direct a film based on the novel. However, the book received mixed reviews with Cassidy Ward of BigShinyRobot writing: "it lacks the kinds of excitement and palpable danger I was expecting and hoping for ... Artemis is a little more fiction and a little less science, and the story suffers for it. Weir brings the same wit and the same love of details (as he did in The Martian) but it never quite feels real enough to lurch your stomach when things go wrong." Weir had considered writing a sequel to Artemis, but ultimately decided against it due to the lackluster reception it received. The film adaptation languished in development hell and, ultimately, Phil Lord and Chris Miller decided to direct Weir's follow up book Project Hail Mary, instead.
In 2017, CBS picked up a pilot written by Weir titled Mission Control, following a group of young NASA astronauts and scientists. In May of that year, Weir collaborated with webcomic artist Sarah Andersen to reillustrate Cheshire Crossing for Tapas, before publishing it as a stand-alone graphic novel in July 2019. In November 2019, a film adaptation of Cheshire Crossing was announced from Amblin Partners and Walt Disney Pictures, to be produced by Michael De Luca and written by Erin Cressida Wilson.
In May 2021, Weir released his third novel, Project Hail Mary. It centers on Ryland Grace, a teacher and former biologist who wakes up afflicted with amnesia aboard a spacecraft. It received widespread positive reviews, winning the 2022 Audie Award for Audiobook of the Year and a nomination for the 2022 Hugo Awards for Best Novel, as well as achieving the #1 spot on the New York Times Audiobook Bestseller List. Ryan Gosling stars as Grace in a film adaption, with Lord and Miller directing the project.
In 2015, he lived in Mountain View, California, in a rented two-bedroom apartment. Due to his fear of flying, he never visited the set of the film adaptation of The Martian in Budapest, which is where most of the scenes set on Mars were shot. In 2015, with the help of therapy and medication, he flew to Houston to visit the Johnson Space Center and to San Diego to attend San Diego Comic-Con.
Weir is married to Ashley Weir, whom he met while he was in Los Angeles to pitch a TV series. They have one son, born in 2021.
Weir has said that he is agnostic, and has described his political views as fiscally conservative and socially liberal. He has stated to have aphantasia, having very little visual imagination.
Weir's original website lists his works, with free versions of many of his short stories.