Glen Campbell was born in Billstown, a tiny community near Delight in Pike County, Arkansas. He was the seventh son of 12 children. His father was a sharecropper of Scottish descent. He started playing guitar as a youth without learning to read music. He credits his uncle Boo for teaching him the guitar.
In 1954 Campbell moved to Albuquerque to join his uncle’s band known as Dick Bills and the Sandia Mountain Boys. There he also appeared on his uncle’s radio show and on K Circle B Time, the local children's program on KOB television. In 1958 Campbell formed his own band, the Western Wranglers.
In 1960, Campbell moved to Los Angeles to become a session musician. Around that time he was part of the group the Champs. Soon Campbell was in great demand as a session musician. He was part of a group of studio musicians that became known as "the Wrecking Crew". During this period he played on recordings by Bobby Darin, Ricky Nelson, Dean Martin, Nat King Cole, The Monkees, Nancy Sinatra, Merle Haggard, Jan and Dean, Elvis Presley, Frank Sinatra and Phil Spector.
From December 1964 to early March 1965, Campbell was a touring member of the Beach Boys, filling in for Brian Wilson. He also played guitar on the group's Pet Sounds album, among other recordings. On tour, he played bass guitar and sang falsetto harmonies.
In 1967 Campbell was the uncredited lead vocalist on "My World Fell Down" by Sagittarius, a studio group. The song reached No. 70 on the Billboard Hot 100.