Peter Seeger (May 3, 1919 – January 27, 2014) was an American folk singer and social activist. A fixture on nationwide radio in the 1940s, he also had a string of hit records during the early 1950s as a member of the Weavers, most notably their recording of Lead Belly's "Goodnight, Irene", which topped the charts for 13 weeks in 1950. Members of the Weavers were blacklisted during the McCarthy Era. In the 1960s, Seeger re-emerged on the public scene as a prominent singer of protest music in support of international disarmament, civil rights, counterculture, and environmental causes.

A prolific songwriter, his best-known songs include "Where Have All the Flowers Gone?" (with Joe Hickerson), "If I Had a Hammer (The Hammer Song)" (with Lee Hays of the Weavers), and "Turn! Turn! Turn!" (lyrics adapted from Ecclesiastes), which have been recorded by many artists both in and outside the folk revival movement and are sung throughout the world. "Flowers" was a hit recording for the Kingston Trio (1962); Marlene Dietrich, who recorded it in English, German and French (1962); and Johnny Rivers (1965). "If I Had a Hammer" was a hit for Peter, Paul and Mary (1962) and Trini Lopez (1963) while the Byrds had a number one hit with "Turn! Turn! Turn!" in 1965.

Seeger was one of the folk singers responsible for popularizing the spiritual "We Shall Overcome" (also recorded by Joan Baez and many other singer-activists) that became the acknowledged anthem of the Civil Rights Movement, soon after folk singer and activist Guy Carawan introduced it at the founding meeting of the Student Nonviolent Coordinating Committee (SNCC) in 1960. In the PBS American Masters episode "Pete Seeger: The Power of Song", Seeger stated it was he who changed the lyric from the traditional "We will overcome" to the more singable "We shall overcome".