Jerry Williams Jr. (born July 12, 1942), generally credited under the pseudonym Swamp Dogg after 1970, is an American country soul and R&B singer, musician, songwriter and record producer. Williams has been described as "one of the great cult figures of 20th century American music."

After recording as Little Jerry and Little Jerry Williams in the 1950s and 1960s, he reinvented himself as Swamp Dogg, releasing a series of satirical, offbeat, and eccentric recordings, as well as continuing to write and produce for other musicians. He debuted his new sound on the Total Destruction to Your Mind album in 1970. In the 1980s, he helped to develop Alonzo Williams' World Class Wreckin' CRU, which produced Dr. Dre among others. He continues to make music, releasing Love, Loss, and Auto-Tune on Joyful Noise Recordings in 2018, Sorry You Couldn't Make It in 2020, and I Need a Job...So I Can Buy More Auto-Tune in 2022 on Don Giovanni Records. In 2024, he released Blackgrass: From West Virginia to 125th St on Oh Boy, a label founded by the late John Prine.