Mark Snow (born Martin Fulterman; August 26, 1946) is an American composer for film and television. Among his most famous compositions is the theme music for science fiction television series The X-Files.

The X Files instrumental was released as a single in the United Kingdom, where the series aired on BBC Two and BBC One, in early-1996, peaking at number two on the UK Singles Chart. Snow also wrote the music for another Chris Carter series, Millennium, and the background music scores for both shows, a total of 12 seasons. Snow composed scores for other notable television, including Hart to Hart, Starsky & Hutch (season 3), and Smallville.