On April 9, 1965, Johnston joined the Beach Boys in New Orleans, replacing Glen Campbell, who briefly filled in as a touring member for Brian Wilson, and had declined an offer to officially join the band. Johnston did not start playing bass until his first tenure with the Beach Boys, and the first contributions Johnston made as one of the Beach Boys was on Summer Days (And Summer Nights!!). For contractual reasons, however, he would not be credited or photographed on a Beach Boys album cover until Wild Honey in 1967. Johnston has been credited by the Library of Congress as one of the original greatest supporters of the Beach Boys' 1966 signature album Pet Sounds. He flew to London in May 1966 and played the album for John Lennon, Paul McCartney, and Keith Moon, who was a notable Beach Boys fan. Johnston wrote several Beach Boys songs during this period, starting with the instrumental "The Nearest Faraway Place" off the album 20/20. His most notable written composition for the band during this period was "Disney Girls (1957)", which appeared on Surf's Up and was subsequently recorded by, among others, Cass Elliot, Captain & Tennille, Art Garfunkel, Jack Jones, and Doris Day.