Pitti-Sing is a character in the Gilbert and Sullivan operetta, The Mikado. She is the sister of Yum-Yum and Peep-Bo, and the ward of Ko-Ko. She, Ko-Ko and Pooh-Bah are falsely blamed for the execution of Nanki-Poo, and the trio is condemned to death. However, they are able to prove their innocence at the last possible moment, and Katisha arranges for them to be pardoned.
The role of Pitti-Sing is usually sung by a mezzo-soprano, but an alto could also play the role. She doesn't have any proper solos, but she sings a stanza by herself in "The Criminal Cried," and leads the chorus in "Braid the Raven Hair" and "For He's Going to Marry Yum-Yum."
Pitti-Sing may not be a major role in The Mikado, but she is still vital to the plot.