The Masked Singer (abbreviated as TMS) is an American reality singing competition television series that premiered on Fox on January 2, 2019. It is part of the Masked Singer franchise that originated from the South Korean version of the show King of Mask Singer, which features celebrities singing songs while wearing head-to-toe costumes and face masks concealing their identities. Hosted by Nick Cannon, the program employs panelists who guess the celebrities' identities by interpreting clues provided to them throughout each season. Ken Jeong, Jenny McCarthy Wahlberg, Rita Ora, and Robin Thicke appear in each episode and vote alongside an audience for their favorite singer after all performances have concluded. The least popular is eliminated, taking off their mask to reveal their identity.

To prevent their identities from being revealed before each prerecorded episode is broadcast, the program makes extensive use of code names, disguises, non-disclosure agreements, and a team of security guards. While television critics have had mixed reviews for the series and particularly negative opinions of its panelists, the costumes have attracted praise. Inspired by haute couture, they were designed in the first six seasons by Marina Toybina, who won a Costume Designers Guild Award and two Creative Arts Emmy Awards. Other production staff won or received nominations for various labor union awards, and the show has won or been nominated for awards presented by the Academy of Television Arts & Sciences, Critics Choice Association, and Hollywood Critics Association.

The first five seasons received the highest Nielsen ratings for a non-sports program in the key demographic of adults 18–49. Two spin-offs—an aftershow and a dance version, The Masked Dancer—followed as a result. The growth of the Masked Singer franchise has been credited to the show's success, as has an interest in adapting similar South Korean reality television series and other television formats centered on costumes. Media and merchandise associated with the series includes a podcast, clothing, accessories, NFTs, and a stage show. The series has been renewed for a twelfth season, which premiered on September 25, 2024.