Thin may refer to: * a lean body shape. ''(See also: emaciation, underweight)'' * Thin (film), ''Thin'' (film), a 2006 HBO documentary about eating disorders * Paper Thin (disambiguation), referring to multiple songs * Thin (web server), a Ruby web-server based on Mongrel (web server), Mongrel *Thin (name)

* * * Thin client, a computer in a client-server architecture network. * Thin film, a material layer of about 1 μm thickness. * Thin-film deposition, any technique for depositing a thin film of material onto a substrate or onto previously deposited layers * Thin film memory, high-speed variation of core memory developed by Sperry Rand in a government-funded research project * Thin-film optics, the branch of optics that deals with very thin structured layers of different materials * Thin layer chromatography (TLC), a chromatography technique used in chemistry to separate chemical compounds * Thin layers (oceanography), congregations of phytoplankton and zooplankton in the water column * Thin lens, lens with a thickness that is negligible compared to the focal length of the lens in optics * Thin Lizzy, Irish rock band formed in Dublin in 1969 * Thin Man (disambiguation) * The Thin Blue Line (disambiguation) * Thin capitalisation {{disambiguation