Route 666 may refer to:
Highways
Canada Alberta Highway 666 Ontario Highway 666, renumbered to 658 in 1985
Ireland R666 road (Ireland)
United Kingdom A666 road
United States U.S. Route 666, renumbered in 2003 to U.S. Route 491 Florida State Road 666 County Route 666 (Atlantic County, New Jersey) Ohio State Route 666 Pennsylvania Route 666
Media Comics Route 666 (comics), a 2002 comic book published by CrossGen Comics
Music Route 666 (Helltrain album), 2006 Route 666 (The Iron Maiden album), 2007 Route 666 (The Hamsters album), 1995 "Route 666", a song by God Is an Astronaut from The End of the Beginning "Route 666", a song by The Comsat Angels from My Mind's Eye "Route 666", a song by BB Tone from Natural Born Killers "Route 666", a song by L'Arc-en-Ciel from Real "Hwy 666", a song by Corey Taylor from the 2022 album CMFT
Film and television Route 666 (film), a 2001 American horror film Route 666: America's Scariest Home Haunts, an Internet TV series "Route 666" (Married... with Children), an episode of Married... with Children "Route 666" (Supernatural), an episode of Supernatural "Route 666", a fictional funhouse ride in the 2004 film The Machinist
Video games Ride to Hell: Route 666, a cancelled digitally distributed spinoff of Ride to Hell: Retribution