The Serenade for strings in G major, better known as Eine kleine Nachtmusik ("A little night music"), is one of the most popular compositions by Wolfgang Amadeus Mozart. It is K. 525 in the Köchel catalogue of Mozart's works.

The work was written for a chamber ensemble of two violins, viola, and cello with optional double bass (it is often performed today with more than one person to a part). The opening tune of the first movement is widely known. This first movement is an allegro in sonata form, with the first subject of the exposition in the key of G major and the second subject in D major. The exposition is then repeated. The development section touches on D minor and C major before the work returns to G major for the recapitulation (a repetition of the exposition with both subjects in the same key, as is convention).

The second movement is a "Romanze", the third is a minuet and trio in ternary form, and the fourth and last is in rondo form.