Horizontal may refer to:
- Horizontal plane, in astronomy, geography, geometry and other sciences and contexts
- Horizontal coordinate system, in astronomy
- Horizontalism, in monetary circuit theory
- Horizontalism, in sociology
- Horizontal market, in microeconomics
- Horizontal (album), a 1968 album by the Bee Gees
- "Horizontal" (song)" is a 1968 song by the Bee Gees
