Something Rotten! is a musical comedy with a book by John O'Farrell and Karey Kirkpatrick and music and lyrics by Karey and Wayne Kirkpatrick. Set in 1595, the story follows the Bottom brothers, Nick and Nigel, who struggle to find success in the theatrical world as they compete with the wild popularity of their contemporary William Shakespeare.

Something Rotten! opened on Broadway at the St. James Theatre on April 22, 2015, where it played for 708 performances. It was nominated for ten Tony Awards, including Best Musical, and won one for Best Featured Actor in a Musical (Christian Borle). Tours and international productions have followed.

The musical began with an idea that brothers Karey and Wayne Kirkpatrick had had since the 1990s. They finally joined with John O'Farrell to write several songs and presented those songs and a treatment to the producer Kevin McCollum in 2010. The team then joined with Casey Nicholaw, who brought in several of the actors, resulting in the workshop in 2014.

Something Rotten! was expected to have a pre-Broadway tryout at the 5th Avenue Theatre, Seattle, Washington, in April 2015. However, when a Broadway theatre became available, Kevin McCollum decided to open the show without the Seattle tryout. "David Armstrong, artistic director of 5th Avenue Theater, said ... that after the positive buzz surrounding the musical's workshop in October [2014], he and Mr. McCollum began discussing the possibility of the show bypassing Seattle in favor of Broadway." The developmental lab took place in New York City in October 2014 with Casey Nicholaw as director and choreographer.

Something Rotten! began previews on Broadway at the St. James Theatre on March 23, 2015, and officially opened on April 22, starring Christian Borle as William Shakespeare, Brian d'Arcy James as Nick Bottom, John Cariani as Nigel Bottom, Heidi Blickenstaff as Bea Bottom and Brad Oscar as Thomas Nostradamus. It was directed and choreographed by Casey Nicholaw, with the sets designed by Scott Pask, costumes by Gregg Barnes and lighting by Jeff Croiter. The production closed on January 1, 2017 after 742 performances. It was nominated for ten Tony Awards, including Best Musical, and won one (for Borle as Best Featured Actor in a Musical).

The show launched a US national tour with previews at Proctor's Theatre in Schenectady, New York on January 10, 2017, before officially opening at the Boston Opera House on January 17. The tour cast featured Rob McClure (Nick Bottom), Adam Pascal (Shakespeare) and Josh Grisetti (Nigel Bottom).

The show also launched a Non-Equity national tour beginning on September 19, 2018 at the RiverCenter for the Performing Arts in Columbus, Georgia. The tour starred Matthew Janisse (Nick Bottom), Matthew Baker (Shakespeare), and Richard Spitaletta (Nigel Bottom) and was staged by Steve Bebout (associate director of the original Broadway production). In June 2019, the show played a short run of June 9–30 at the Chungmu Art Center Grand Theater in Seoul, South Korea, marking the final destination on the tour.

A Swedish-language production ran from November 8, 2018 to March 3, 2019 at the Wermland Opera in Karlstad, Sweden, directed by Markus Virta. The translation was by Calle Norlén. A South Korean production in Korean played in late 2020, at the Chungmu Art Center Grand Theater, though some of the performances were cancelled due to the COVID-19 pandemic. A Czech-language production played from June 19 to 23, 2021, from September 2021 to June 2022, and on May 22, 2023, at Nová Scéna, produced by J. K. Tyl Theatre, in Plzeň, Czech Republic. The translation was by Pavel Bár and the director, Lumír Olšovský.