Gray Line or Grey Line may refer to:

Transportation

  • Gray Line Worldwide, an international sightseeing bus operator
  • Grey Line (Bangkok), a planned monorail line in Bangkok, Thailand
  • Grey Line (Delhi Metro), Delhi, India
  • Gray Coach, a former Canadian inter-city bus line based in Toronto
  • E Embarcadero, San Francisco, California
  • Jubilee line, London, England
  • Line 6 Finch West, Toronto, Canada
  • Line 9 (Shenzhen Metro), Shenzhen, China
  • Metro (Minnesota), lettered lines are color-coded "METRO Gray", Minneapolis—Saint Paul, Minnesota
  • Olympic Park railway line, Sydney, Australia
  • Pujiang line, Shanghai, China
  • Serpukhovsko-Timiryazevskaya line, known as the Grey Line, Moscow, Russia

New York City Subway

  • BMT Canarsie Line
  • L (New York City Subway service)
  • S (New York City Subway service), three separate rapid transit subway shuttles

Other uses

  • Grayline lascar
  • Terminator (solar) or grey line, delimiting the illuminated and dark sides of a planetary body
  • The Long Gray Line