Styx may refer to:
- Styx (mythology), the river that forms the boundary between the Greek underworld and the world of the living, as well as a goddess and a nymph that represent the river
in chemistry:
- Styx numbers or styx rules, a method of describing bonding in boranes
in geography:
- Styx River (disambiguation), any of various geographical rivers named for the mythological one
- Styx forest, a forest in Tasmania, Australia
- Styx River State Forest, a forest in New South Wales, Australia
in popular culture:
- Styx (band), an American rock band
- Styx (album), the first album released by the band Styx in 1972
- Styx (film), a 2001 movie, starring Peter Weller
- Styx, a UK band involving Bruce Dickinson prior to Iron Maiden
- River Styx Magazine, based in St Louis, Missouri and associated poetry-reading sessions
in computing:
- Styx (parser), a scanner and parser generator
- Styx (game), a 1983 computer game by Windmill Software.
- Styx (Spectrum game), a 1983 computer game for the ZX Spectrum, released by Bug-Byte Software.
- Styx (protocol), the network protocol at the heart of the Inferno operating system
in military technology:
- SS-N-2 Styx, NATO reporting name for the Soviet P-15 Termit missile
