Impressionism in music was a movement among various composers in Western classical music (mainly during the late 19th and early 20th centuries) whose music focuses on mood and atmosphere, "conveying the moods and emotions aroused by the subject rather than a detailed tone‐picture". "Impressionism" is a philosophical and aesthetic term borrowed from late 19th-century French painting after Monet's Impression, Sunrise. Composers were labeled Impressionists by analogy to the Impressionist painters who use starkly contrasting colors, effect of light on an object, blurry foreground and background, flattening perspective, etc. to make the observer focus their attention on the overall impression.

The most prominent feature in musical Impressionism is the use of "color", or in musical terms, timbre, which can be achieved through orchestration, harmonic usage, texture, etc. Other elements of musical Impressionism also involve new chord combinations, ambiguous tonality, extended harmonies, use of modes and exotic scales, parallel motion, extra-musicality, and evocative titles such as “Reflets dans l'eau” (“Reflections on the water”), “Brouillards” (“Mists”), etc.