The Styx is a goddess and a river in Greek mythology that formed the boundary between Earth and the Underworld.
Styx River or River Styx may also refer to:
Geography
Municipalities
- River Styx, Ohio, a community in Medina County, Ohio
Rivers
Australia
- Styx River (East Central Queensland)
- Styx River (New South Wales)
- Styx River (Tasmania)
- Styx River (West Central Queensland)
New Zealand
Russia
United States
- Styx River (Alabama)
- River Styx (Georgia)
- River Styx, a semi-subterranean stream in Mammoth Cave National Park, Kentucky
- River Styx (Gratiot County, Michigan)
- River Styx (Marquette County, Michigan)
- Styx River (Ohio)
- River Styx, the subterranean portion of Cave Creek in Oregon Caves National Monument and Preserve
- Styx Branch, a stream in Tennessee
Arts, entertainment, and media
- "River Styx", a song by Black Rebel Motorcycle Club from Beat the Devil's Tattoo
- River Styx, the Nile River in Robert E. Howard's fictional Hyborian Age
- River Styx Magazine, a magazine based in St Louis, Missouri
- River Styxx, a character in the Monster High franchise
- The River Styx (painting) or La Laguna Estigia, a painting by Felix Resurreccion Hidalgo
Other
- River Styx archaeological site, in Alachua County, Florida