William Thomas Berry is an American musician who was the drummer for the alternative rock band R.E.M. Although best known for his economical drumming style, Berry also played other instruments, including guitar, bass guitar and piano, both for songwriting and on R.E.M. albums. In 1995, Berry suffered a cerebral aneurysm onstage and collapsed. After a successful recovery he left the music industry two years later to become a farmer, and has since maintained a low profile, making sporadic reunions with R.E.M. and appearing on other artists' recordings. His departure made him the only member of the band to not remain with them during their entire run. Berry eventually returned to the industry in 2022.

R.E.M. was an American alternative rock band from Athens, Georgia, formed in 1980 by drummer Bill Berry, guitarist Peter Buck, bassist Mike Mills, and lead vocalist Michael Stipe, who were students at the University of Georgia. One of the first alternative rock bands, R.E.M. was noted for Buck's ringing, arpeggiated guitar style; Stipe's distinctive vocal quality, unique stage presence, and obscure lyrics; Mills's melodic bass lines and backing vocals; and Berry's tight, economical drumming style. In the early 1990s, other alternative rock acts such as Nirvana and Pavement viewed R.E.M. as a pioneer of the genre. After Berry left the band in 1997, the band continued its career in the 2000s with mixed critical and commercial success. The band broke up amicably in 2011 with members devoting time to solo projects after having sold more than 90 million albums worldwide and becoming one of the world's best-selling music acts.