Blue Line or Blueline may refer to:

Transportation

Asia

China

  • Line 2 (Beijing Subway), Beijing, China
  • Island line (MTR), Hong Kong, China

India

  • Blue Line (Namma Metro), Bengaluru, India
  • Blue Line (Chennai Metro), Chennai, India
  • Blue Line (Delhi Metro), Delhi, India
  • Blue Line (Hyderabad Metro), Hyderabad, India
  • Blue Line (Kolkata Metro), Kolkata, India
  • Blue Line (Lucknow Metro), Lucknow, India
  • Blue Line (Mumbai Metro), Mumbai, India

South Korea

  • Busan Metro Line 4, Busan, South Korea
  • Seoul Subway Line 1, Dark Blue Line, Seoul, South Korea
  • Seoul Subway Line 4, Light Blue Line, Seoul, South Korea

Taiwan

  • Blue line (Taichung MRT), Taichung, Taiwan
  • Bannan line, Taipei, Taiwan

Others

  • Blue Line (Bangkok), Bangkok, Thailand
  • Blue Line (Dubai Metro), Dubai
  • Cikarang Line of KRL Commuterline, Jakarta, Indonesia
  • Manila Light Rail Transit System Line 2, Manila, Philippines
  • Line 1 (Riyadh Metro), Blue Line, Riyadh, Saudi Arabia
  • Downtown Line, Singapore
  • Blue Line (Yokohama), also called Lines 1 & 3, Yokohama, Japan
  • Blue Line (Jerusalem Light Rail)

Europe

  • Blue Line (airline), based in France
  • Blue Line (Lisbon Metro), Portugal
  • Blue Line (Stockholm Metro), Sweden
  • Blue Line International, a former ferry service in the Adriatic Sea
  • Barcelona Metro line 5, often called "Línia Blava" (Blue Line), Barcelona, Spain
  • Barcelona Metro line 6, Barcelona, Spain
  • Paris Metro Line 2, Paris, France
  • Piccadilly line, London, England
  • Sheffield Supertram Blue Line, United Kingdom
  • Tyne and Wear Metro of Newcastle upon Tyne, UK (Former line)
  • Victoria line, London, England

North America

New York City

  • The Harlem Line of the Metro-North Railroad
  • The Hoboken–33rd Street route of the PATH Train
  • Any of the New York City Subway services that use the IND Eighth Avenue Line and its branches:
  • A Eighth Avenue Express
  • C Eighth Avenue Local
  • E Eighth Avenue Local
  • The former K Eighth Avenue Local
  • The Rockaway Park Shuttle, which formerly contained a blue route bullet
  • The Port Jefferson Branch of the Long Island Rail Road
  • The former JFK Express of the New York City Subway
  • The future T Second Avenue Local of the New York City Subway
  • The West Hempstead Branch of the Long Island Rail Road
  • The Staten Island Railway

Other

  • ARTx Blue Line, formerly Rapid Ride, Albuquerque, New Mexico
  • Blue Line (MARTA), Atlanta, Georgia
  • Blue Line (CapMetro), Austin, Texas
  • Blue Line (MBTA), Boston, Massachusetts
  • Blue Line (Calgary), Calgary, Alberta, Canada
  • Lynx Blue Line, Charlotte, North Carolina
  • Blue Line (CTA), Chicago, Illinois
  • Blue Line (RTA Rapid Transit) (light rail), Cleveland, Ohio
  • Blue Line (DART), Dallas, Texas
  • Trinity Railway Express, Dallas, Texas
  • H Line (RTD), Denver, Colorado
  • A Line (Los Angeles Metro), Los Angeles County, California
  • Blue Line (Mexico City Metro), Mexico
  • Blue Line (Mexico City Metrobús), Mexico
  • Metro Blue Line (Minnesota), Minneapolis, Minnesota
  • Blue Line (Montreal Metro), Montreal, Quebec
  • Atlantic City Line, a commuter rail line New Jersey
  • Grove Street – Newark Penn, a light rail line in Newark, New Jersey
  • North Jersey Coast Line, a commuter rail line New Jersey
  • Blue Line (Pittsburgh), Pittsburgh, Pennsylvania
  • Market–Frankford Line, Philadelphia, Pennsylvania
  • Blue Line (SacRT), Sacramento, California
  • Blue Line (San Diego Trolley), San Diego, California
  • Blue Line (BART), San Francisco Bay Area, California
  • N Judah, a Muni Metro light rail line in San Francisco, California
  • Line 3 Scarborough, Toronto, Canada
  • Viva Blue, York Region, Ontario
  • MAX Blue Line, Portland, Oregon
  • Blue Line (St. Louis MetroLink), St. Louis, Missouri
  • Blue Line (Sound Transit), a proposed extension in Seattle, Washington
  • Swift Blue Line, Snohomish County, Washington
  • Blue Line (TRAX), a light rail line in the Salt Lake City, Utah area
  • Blue Line (Washington Metro), Washington, DC
  • Tomorrowland Transit Authority PeopleMover, Walt Disney World, Florida
  • Line 4 (O-Train), the Airport Link of Ottawa's O-Train (Line 4)

South America

  • Line 1 (São Paulo Metro), São Paulo, Brazil

Africa

  • Blue Line (Lagos Transit), Lagos, Nigeria
  • Blue Line, part of the Abuja Light Rail Network in Abuja Nigeria

Other

  • Blue Line (album), by Yae
  • Blue line (ice hockey), the line between center ice and each team's zone
  • Blue Line (withdrawal line), the UN drawn demarcation line dividing Lebanon from Israel and the Golan Heights
  • Blue Line (New York State), delineates the Adirondack and Catskill parks of New York's Forest Preserve
  • BlueLine Grid, a mobile communications platform that connects civil service employees
  • Blueline, a 2019 EP by twlv
  • The "blue line", mark on an airspeed indicator for a multi-engine aircraft
  • The blue-line printing process for copying using the diazo chemical process, also known as whiteprint
  • The Blueline Blaster, nickname of Hy Buller (1926–1968), All Star NHL ice hockey player
  • Blue line, a diagram in method ringing which shows the structure of a method
  • Blue-line stream, year-round streams that are typically denoted on maps with solid blue lines
  • "Blue Lines", a song by the American band Bright from the album Full Negative (or) Breaks