Rivers Cuomo (/ˈkwoʊmoʊ/ KWOH-moh; born June 13, 1970) is an American musician and the lead vocalist, guitarist, and primary songwriter of the rock band Weezer. Cuomo was born in New York City and raised in several Buddhist communities around the northeast US until the age of 10, when his family settled in Connecticut. He played in several bands in Connecticut and California before forming Weezer in 1992.

After the success of Weezer's debut, the Blue Album (1994), Cuomo enrolled at Harvard University, but dropped out after recording Weezer's second album, Pinkerton (1996). He re-enrolled and graduated in 2006. Though Pinkerton is now frequently cited among the best albums of the 1990s and has been certified platinum, it was initially a commercial and critical failure, pushing Cuomo's songwriting toward pop music for Weezer's next album, the Green Album (2001). Weezer has released more than a dozen albums since.

Cuomo has released several compilations of demos, including Alone: The Home Recordings of Rivers Cuomo (2007) and Alone II: The Home Recordings of Rivers Cuomo (2008), and has released thousands of home recordings on his website. He has collaborated with artists including Hayley Williams, B.O.B., AJR, Todd Rundgren and Panic! at the Disco. With the American songwriter Scott Murphy, Cuomo has released two Japanese-language albums as Scott & Rivers.

Rivers Cuomo was born on June 13, 1970, in New York City to Frank Cuomo, of Italian descent, and Beverly Shoenberger, of German-English descent. Frank was a musician who played drums on Wayne Shorter's 1971 album Odyssey of Iska. According to one account, Cuomo's mother named him Rivers either because he was born between the East and Hudson rivers in Manhattan or because she could hear a river outside her hospital window. However, his father said Rivers was named after the soccer players Rivellino, Gigi Riva, and Gianni Rivera, all of whom were playing in the 1970 World Cup in Mexico.

Cuomo was raised in Rochester, New York, at the Rochester Zen Center. After his father left in 1975, his mother relocated the family to Yogaville, an ashram in Pomfret, Connecticut. Cuomo attended the Pomfret Community School and his mother married Stephen Kitts. In 1980, when Yogaville relocated to Virginia, the family stayed in Connecticut and moved to the Storrs/Mansfield area. During this time, Cuomo attended Mansfield Middle School and E.O. Smith High School. He was a member of the high school choir and performed in a school production of Grease as Johnny Casino. While in high school, Cuomo attended a summer program at the Berklee College of Music. He was a fan of hair bands during this time, such as Kiss and Quiet Riot. He also changed his name to Peter Kitts while in high school, but after graduating, he reverted to his original name.

One of Cuomo's earliest music projects was the glam metal band Avant Garde. In 1989, after playing several shows in Connecticut, Avant Garde moved to Los Angeles and changed its name to Zoom. It broke up in 1990. During this time, Cuomo attended Santa Monica College. In 1990 and 1991, while Cuomo was writing material for what became Weezer's debut album, he was a roadie for the band Kingsize. He also worked at Tower Records on Sunset Boulevard, where he met the drummer Patrick Wilson. Cuomo began to move away from metal and absorbed alternative influences such as Nirvana, the Pixies and Sonic Youth. He also listened to the Beach Boys and the Beatles, which influenced his songwriting. He did not want audiences to realize he had once been a metal musician, as "there was so much anxiety about authenticity at the time". He also began to think of himself as a singer for the first time.

Cuomo formed Weezer in 1992 with Wilson, the bassist Matt Sharp and the guitarist Jason Cropper. "Weezer" was the nickname Cuomo's father gave him when he was a toddler. On June 25, 1993, Weezer signed with DGC, a subsidiary of Geffen Records. They released their self-titled debut album, commonly known as the Blue Album, in May 1994. Cropper was fired during the recording and replaced by Brian Bell.

The Blue Album was certified platinum on January 1, 1995, with sales of over one million. Cuomo tired of the monotony and loneliness of touring and developed a "huge inferiority complex" about rock music, saying: "I thought my songs were really simplistic and silly, and I wanted to write complex, intense, beautiful music."