The Fantasticks is a 1960 musical with music by Harvey Schmidt and lyrics by Tom Jones. It tells an allegorical story, loosely based on the 1894 play The Romancers (Les Romanesques) by Edmond Rostand, concerning two neighboring fathers who trick their children, Luisa and Matt, into falling in love by pretending to feud.

The show's original off-Broadway production ran a total of 42 years (until 2002) and 17,162 performances, making it the world's longest-running musical. The musical was produced by Lore Noto. It was awarded Tony Honors for Excellence in Theatre in 1991. The poetic book and breezy, inventive score, including such familiar songs as "Try to Remember", helped make the show durable. Many productions followed, as well as television and film versions. The Fantasticks has become a staple of regional, community and high school productions since its premiere, with approximately 250 new productions each year. It is played with a small cast, two- to three-person orchestra and minimalist set design.

The show was revived off-Broadway from 2006 to 2017. As of 2010, its original investors had earned 240 times their original investments. The musical has played throughout the US and in at least 67 foreign countries.

An off-Broadway theatre is any professional theatre venue in New York City with a seating capacity between 100 and 499, inclusive. These theatres are smaller than Broadway theatres, but larger than off-off-Broadway theatres, which seat fewer than 100.

An "off-Broadway production" is a production of a play, musical, or revue that appears in such a venue and adheres to related trade union and other contracts. Some shows that premiere off-Broadway are subsequently produced on Broadway.