Cyan, Inc., doing business as Cyan Worlds, is an American video game developer and publisher based in Mead, Washington. Founded by brothers Rand and Robyn Miller in 1987, the company created the Myst series.

Myst became the best-selling PC game ever made when it was released in 1993, and remained so for several years afterwards. It spawned several sequels, including Riven and the massively multiplayer online adventure Myst Online: Uru Live. Before Myst, the company created children's games such as The Manhole. In 2016, they released the Kickstarter-funded game Obduction and in 2023, they released Firmament, also funded with Kickstarter.

As of 2024, Cyan is the oldest surviving independent game studio in the United States.

Cyan was founded in 1987 by brothers Rand and Robyn Miller, operating out of their parents' basement in their Spokane, Washington home. Rand had been programming games as a junior high school student in the 1980s, while Robyn studied music and arts in high school. The two found a common ground through the Macintosh Hypercard development program which allowed them to mix their talents together. Cyan originally produced adventure games for children. The company's early titles, The Manhole (1988), Cosmic Osmo and the Worlds Beyond the Mackerel (1989) and Spelunx (1991) were whimsical fantasy adventures for a young audience. The games offered numerous graphical screens with puzzles, mini-games and activities. Some of these titles were early forays of Cyan into both construction of interactive worlds using HyperCard and the CD-ROM medium, both of which would later be used for Myst.

In 1993, Cyan shot to worldwide fame with the release of Myst, a 3D pre-rendered adventure game aimed at an older audience unlike their previous games. Myst was one of the earliest CD-ROM games during a time when CD-ROM drives were beginning to become mainstream. The title sold more than six million copies and was the best-selling PC game ever, until The Sims exceeded Myst sales in 2002.

With the revenue from Myst, Cyan rebranded as Cyan Productions and quickly moved to a new headquarters to accommodate a bigger staff, where they remain today. During this time, three novels set in the Myst universe were co-authored by the Millers and David Wingrove. The sequel to Myst, Riven, was released in 1997. After its release, Robyn opted to leave Cyan to pursue other interests, primarily working on independent film production. In a 1999 interview, Robyn stated that the reason for his departure was that "Two people can't pilot a ship – someone must be in charge...The parting gave us each a ship."

The next eight years saw a huge amount of expansion in the Myst franchise, both from within and outside of Cyan. While the publishing rights were transferred from Broderbund to Mattel, and then to Ubisoft, Cyan prepared for the next game in the Myst universe, which was to be a massively multiplayer online game, and not a direct sequel to Myst. During this time, the company started going by the name "Cyan Worlds, Inc.". Partly as a test of their new real-time 3D engine, Cyan released realMyst in 2000, a complete recreation of the original Myst game. At the same time, the next Myst game, Myst III: Exile, was developed by Presto Studios and published by Ubisoft, and released in 2001.

In 2003, Cyan announced that their multiplayer adventure, Uru, formerly known under the working titles DIRT ("D'ni In Real Time"), Mudpie ("Multi-User DIRT – Persistent Interactive Environment"), Parable and Myst Online, would be split into separate single-player and multiplayer components, at the request of the publisher Ubisoft. The single-player component, Uru: Ages Beyond Myst, was released later that year. The multiplayer component, Uru Live had a short beta test, but was cancelled before being officially released.