Orange Line may refer to:
- Orange Line or Delhi Airport Metro Express in Delhi, India
- Orange Line (Chennai Metro), in Chennai, India
- Orange Line (Jaipur Metro), in Jaipur, India
- Orange Line (Kanpur Metro), in Kanpur, India
- Orange Line (Kolkata Metro), in Kolkata, India
- Orange Line (Nagpur Metro), in Nagpur, India
- Orange Line (Namma Metro) a planned line in Bengaluru, India
- Orange Line (Lahore Metro) in Lahore, Pakistan
- Orange Line, KMRT, Kaohsiung, Taiwan
- Orange Line (Bangkok), a planned line in Bangkok, Thailand
- Line 1 (Busan), South Korea
- Line 2 (Incheon), South Korea
- Line 3 (Seoul), South Korea
- U Line, Uijeongbu, South Korea
- Tung Chung line, Hong Kong, China
- Zhonghe-Xinlu Line of Taipei Metro, Taipei, Taiwan
- PNR Metro South Commuter Line, Manila, Philippines
- Ampang Line, Kuala Lumpur
- Circle MRT line, Singapore
- Kaluzhsko-Rizhskaya line, Moscow, Russia
- London Overground, London, UK
- Paris Métro Line 5, Paris, France
- Brussels Metro line 2, Brussels, Belgium
- Line 7 (Madrid Metro), Madrid, Spain
- Barcelona Metro line 9, Barcelona, Spain
- U9 (Berlin U-Bahn), Berlin, Germany
- Broad Street Line, Philadelphia, Pennsylvania
- Eglinton Crosstown line, a light rail line currently under construction in Toronto, Ontario, Canada
- MAX Orange Line, a light rail line in Portland, Oregon
- Orange Line (CTA), Chicago, Illinois
- Orange Line (DART), a light rail line in Dallas, Texas
- G Line (Los Angeles Metro), a busway line in Los Angeles, California formerly known as Orange Line
- Orange Line (MBTA), Boston, Massachusetts
- Orange Line, Metrorail, Florida
- Metro Orange Line (Minnesota), a bus rapid transit line serving Minneapolis, Minnesota
- Orange Line (Montreal Metro), Montreal, Quebec, Canada
- Orange Line (San Diego Trolley), San Diego, California
- Orange Line (Sound Transit), a streetcar line in Tacoma, Washington, United States
- Orange Line (Washington Metro), Washington, DC
- Orange Line (BART), San Francisco Bay Area, California
- Viva Orange, York Region, Ontario, Canada
- IND Sixth Avenue Line in New York City, colored orange on maps, which carries the B D F M trains
- Orange Line (VTA), a light rail in Santa Clara County, California
- Orange Line (CapMetro), a planned light rail line in Austin, Texas
- Orange Line (Mexico City Metro)