Thomas Andrew Lehrer (; born April 9, 1928) is a retired American musician, singer-songwriter, satirist, and mathematician. He has lectured on mathematics and musical theater. He is best known for the pithy, humorous songs that he recorded in the 1950s and 1960s. His songs often parodied popular musical forms, though he usually created original melodies when doing so. A notable exception is "The Elements", where he set the names of the chemical elements to the tune of the "Major-General’s Song" from Gilbert and Sullivan’s Pirates of Penzance.
Lehrer’s early work typically dealt with non-topical subject matter and was noted for its black humor in songs such as "Poisoning Pigeons in the Park". In the 1960s, he produced a number of songs that dealt with social and political issues of the day, particularly when he wrote for the U.S. version of the television show That Was the Week That Was. The popularity of these songs has endured their topical subjects and references. Lehrer quoted a friend’s explanation: "Always predict the worst and you’ll be hailed as a prophet." In the early 1970s, Lehrer largely retired from public performances to devote his time to teaching mathematics and music theater at the University of California, Santa Cruz.