Sidney K. Meier (/ˈmaɪər/ MIRE; born February 24, 1954) is an American businessman and computer programmer. A programmer, designer, and producer of many strategy and simulation video games, including the Civilization series, Meier co-founded MicroProse in 1982 with Bill Stealey and is the Director of Creative Development of Firaxis Games, which he co-founded with Jeff Briggs and Brian Reynolds in 1996. For his contributions to the video game industry, Meier was inducted into the Academy of Interactive Arts and Sciences Hall of Fame.

Meier was born in Sarnia, Ontario, Canada, to parents of Dutch and Swiss descent, which conferred on him both Canadian and Swiss citizenship upon birth. When he was about three years old, his family moved to Detroit, Michigan, where he was raised. At the University of Michigan, he studied history and computer science, graduating with a Bachelor of Arts degree in computer science in 1975.

Following college, Meier worked in developing cash register systems for department stores. During this timeframe, Meier acquired an Atari 800 around 1981, an experience that led him to the realization of the potential for employing computer programming in the creation of video games. He found a co-worker, Bill Stealey, who had a similar interest in developing games, and shared the games that Meier had developed. The two decided to establish a new company for computer game development subsequent to the widespread advancement and growth of the software and personal computer industries, which were developing extensively during the initial years of the 1980s.

Sid Meier has stated on numerous occasions that he emphasizes the "fun parts" of a simulation and throws out the rest.

— Computer Gaming World, 1994

Meier founded MicroProse with Stealey in 1982. After a few initial 2D action games, such as Meier's platformer Floyd of the Jungle, MicroProse settled into a run of flight simulation titles beginning with Hellcat Ace (1982) and continuing with Spitfire Ace (1982), Solo Flight (1983), and F-15 Strike Eagle (1985), all designed and programmed by Meier.

The first appearance of Meier's name on the retail box of a game was as the credited creator of Formula 1 Racing in 1982. In 1984 Stealey began marketing Meier himself, hoping to attract other developers by promoting him as an auteur; by 1986 MicroProse was using Meier's name and face in advertisements for its games. In 1987, the company released Sid Meier's Pirates!, the first game with Meier's name in the title. He later explained that the inclusion of his name was because Pirates! is very different from the company's earlier titles. Stealey decided that Meier's name would make those who purchased the flight simulators more likely to play the game. Stealey recalled: "We were at dinner at a Software Publishers Association meeting, and Robin Williams was there. And he kept us in stitches for two hours. And he turns to me and says 'Bill, you should put Sid's name on a couple of these boxes, and promote him as the star.' And that's how Sid's name got on Pirates, and Civilization."

The idea was successful; by 1992, an entry in Computer Gaming World's poetry contest praised Meier's name as "a guarantee they got it right". While emphasizing that he did not encourage MicroProse promoting his name, Meier did insist on doing all of the work on games himself, including sound and art, until work by artist Michael Haire, whom Stealey had hired for Silent Service (1985), persuaded him. Meier is not always the main designer on titles that carry his name. For instance, Brian Reynolds has been credited as the primary designer behind Sid Meier's Civilization II, Sid Meier's Alpha Centauri, and Sid Meier's Colonization, while Jeff Briggs designed Sid Meier's Civilization III, Soren Johnson led Sid Meier's Civilization IV, Jon Shafer led Sid Meier's Civilization V, and Will Miller and David McDonough were the designers of Sid Meier's Civilization: Beyond Earth.