A Little Night Music is a musical with music and lyrics by Stephen Sondheim and book by Hugh Wheeler. Inspired by the 1955 Ingmar Bergman film Smiles of a Summer Night, it involves the romantic lives of several couples. Its title is a literal English translation of the German name for Mozart's Serenade No. 13 for strings in G major, Eine kleine Nachtmusik. The musical includes the popular song "Send In the Clowns".

Since its original 1973 Broadway production, the musical has enjoyed professional productions in the West End, by opera companies, in a 2009 Broadway revival, and elsewhere, and it is a popular choice for regional groups. It was adapted for film in 1977, with Harold Prince directing and Elizabeth Taylor, Len Cariou, Lesley-Anne Down, and Diana Rigg starring.