David Van Cortlandt Crosby (born August 14, 1941) is an American guitarist, singer, and songwriter. He is best known for being a founding member of The Byrds and Crosby, Stills, Nash & Young (CSN&Y). Crosby is a member of the Rock and Roll Hall of Fame for his work in the Byrds and CSN&Y.

Around the time of Crosby's firing, he met a recently unemployed Stephen Stills at a party at the home of Cass Elliot (Mama Cass) in California in March 1968, and the two started meeting informally together and jamming. They were soon joined by Graham Nash, who left his commercially successful group The Hollies to play with Crosby and Stills.

Their first album, Crosby, Stills & Nash of 1969 was an immediate hit, spawning two Top 40 hit singles and receiving key airplay on the new FM radio format, in its early days populated by unfettered disc jockeys prone to playing entire albums at once.

While in CSN, he wrote many important songs. These include "Guinnevere," "Almost Cut My Hair," "Long Time Gone," and "Delta". He also co-wrote "Wooden Ships" with Paul Kantner of Jefferson Airplane and Stephen Stills.

In 1969, the group was joined by Neil Young, and with him they recorded the album Déjà Vu, which went to number 1 on the charts. That same year, Crosby's longtime girlfriend Christine Hinton was killed in a car accident only days after Hinton, Crosby, and fellow girlfriend Debbie Donovan moved from Los Angeles to the Bay Area. Crosby was devastated, and he began abusing drugs much more severely than he had before. Nevertheless, he still managed to contribute "Almost Cut My Hair" and the title track "Déjà Vu". After the release of the double live album Four Way Street, the group went on a temporary hiatus to focus on their respective solo careers.

David also briefly did a stint with members from the Grateful Dead. Together they recorded "David and the Dorks," a rare live recording at the Matrix on December 15, 1970.