Mathematics and science

• Parallel (geometry)
• Parallel (latitude), an imaginary east-west line circling a globe

Proper name

• Parallel (manga), a shōnen manga by Toshihiko Kobayashi
• Parallel (video), a video album by R.E.M.
• "The Parallel", an episode of The Twilight Zone
• Parallel 9, a British children's television show
• Parallel (Music) an alternative hip hop group based out of Southern California
• Avinguda del Paral·lel, one of the main streets of Barcelona
• "Parallel", the fourth track on Bad Religion's 1996 album The Gray Race

Music

• Parallel key, the minor (or major) key of a major (or minor) key with the same tonic
• Harmonic parallelism, also known as "harmonic planing" or "parallel voice leading"
• Parallel fifths, the concurrence of successive intervals of a perfect fifth between two voices

Other uses

• Parallelism (grammar), a balance of two or more similar words, phrases, or clauses
• Parallel algorithm
• Parallel circuits, as opposed to series
• Parallel computing
• Parallel cousin
• Parallel evolution
• Parallel import, also known as a "grey market product"
• Parallel universe (disambiguation)
• Parallel port
• Parallel communication
• Parallel parking
• Parallel study, a type of clinical study
• Parallel transport, in mathematics using vectors and smooth curves
• Parallels Workstation, virtualization software