Semaphore (disambiguation)

Semaphore is the use of an apparatus with telegraphy to create a visual signal transmitted over long-distances.

It may refer more specifically to:
 * Flag semaphore
 * Semaphore telegraph, a system of long-distance communication based on towers with moving arms
 * Railway semaphore signal for railway traffic control
 * Traffic semaphore, another name for automotive traffic lights based on their early resemblance to railway semaphores
 * Turning semaphore or trafficators, retractable arms to indicate turns on automobiles from the 1920s to 1950s

Other

 * Semaphore (programming), in computer science, a mechanism for supporting mutual exclusion in concurrent programs
 * Semaphore (software), a continuous integration testing utility
 * Semaphore, South Australia, a historic seaside suburb of Adelaide
 * Semaphore railway line, Adelaide, a closed railway line in South Australia
 * Semaphore Corporation (company), a software and publishing firm that operated from 1982 to 2017
 * Semaphore (album), a 1998 album by Fridge
 * "Semaphore" (song), a 2004 single by the New Zealand band Jakob
 * Semaphore, fictional professor in Cubitus comic strips or Wowser cartoons