Mainliner or Mainliners may refer to:

"Mainliner", a person who takes drugs intravenously "Mainliner", a person of the Mainline (Protestant) "Mainliner", a person who lives on the Philadelphia Main Line section of the Philadelphia suburbs "Mainliner", a generic name given to aircraft which flew the Mainline (flight) routes "Mainliner", a specific prefix name given to a number of aircraft operated by United Airlines and possibly others (ex. Mainliner New York, Mainliner Washington, etc.)

In music "Mainliner", a member of The Bryn Mawr Mainliners Men's Barbershop Chorus "Mainliner", a member of Big Tom and The Mainliners, an Irish country music band Mainliner: Wreckage from the Past, a compilation album from the group Social Distortion "Mainliner (band)", is the name of one of the groups formed by Japanese underground musician Asahito Nanjo "Mainliner" is the name of a song by the grindcore group Brutal Truth from their 1994 album Need to Control.

Other Mainliner (racehorse), racehorse that won the 1951 Hambletoninan harness race

See also Mainline (disambiguation)