Scalar may refer to:
- Scalar (mathematics), an element of a field, which is used to define a vector space, usually the field of real numbers
- Scalar (physics), a physical quantity that can be described by a single element of a number field such as a real number
- Lorentz scalar, a quantity in the theory of relativity which is invariant under a Lorentz transformation
- Pseudoscalar, a quantity representable by a mathematical scalar that reacts sensitively to transformations changing the orientation of coordinate systems, e.g. improper rotations, or an object in Clifford algebras and similar settings
- Variable (computing), or scalar, an atomic quantity that can hold only one value at a time
- Scalar particle in physics is a boson subatomic particle whose spin equals zero
See also
- Scalar product, also known as the dot product
- Inner product space
- Scalar field
- Scalar processor
- Scale (music)
- Scaler (video game), 2004
- Pterophyllum scalare (Lichtenstein, 1823), a species of freshwater angelfish
- Scala (disambiguation)