Expression may refer to:

• (in the vernacular) the act or particular way of expressing something (including an emotion through a facial expression or configuration)
• (in mathematics) a mathematical expression
• (in computing) a programming language expression
• (in computing) a vector graphics software Microsoft Expression
• (in genetics) the effect produced by a gene: gene expression
• (in grammar) a particular phrase or cliché, whose meaning may be interpretive or idiomatic.