The Beach Boys lineups

From the start, The Beach Boys have undergone many variations in composition, being represented by fill-ins onstage as often as not. Wilson neighbor David Marks appeared on their first five albums, played with the group in its formative stages, and was a member from 1962 to 1963 as a replacement for Jardine, who had left the group to pursue a career in dentistry. Jardine returned to the band in 1963 as an onstage fill-in for Brian Wilson, who was already feeling the stresses of touring. Marks rejoined the band in 1997, during Carl Wilson's last illness, and remained with them for two years.

Glen Campbell toured for several months with the group in 1965, as a touring replacement for Brian, who had played bass in concert. Campbell was subsequently replaced by Bruce Johnston, who later became a permanent member. During the mid-1970s drummer Ricky Fataar and guitarist Blondie Chaplin joined the band.

Though not corporate members of The Beach Boys, supporting players have featured many notable musicians over the years. Keyboard players Daryl Dragon & Toni Tennille, later famous as the pop duo The Captain & Tennille, toured with the band. Carli Muñoz, who had been playing keyboards with the band since 1970, in 1971 replaced Daryl Dragon as keyboard player until 1979. Mike Meros took over the position from May 1, 1979 to July 4th, 2000. Drummer Mike Kowalski and bassist/guitarist Ed Carter were two of the first outside musicians to join the group in 1969. Percussionist/drummer Bobby Figueroa was added in the mid-seventies until 1984. Adrian Baker joined the band in 1981 as a vocalist/guitarist. Jeff Foskett replaced Baker in 1982 as a guitarist and vocalist and remained with the group until 1989, Foskett is currently a member of Brian Wilson's group. Adrian Baker re-joined the band in 1989 to 1993 as a vocalist/guitarist. Billy Hinsche, of Dino, Desi, & Billy fame, was also a longtime member of the supporting band throughout the '70s, '80s and '90s. Matt Jardine, son of Beach Boy Al Jardine also joined the band in 1989 through 1998 as singer / percussionist. In 1998, Adrian Baker re-joined the band (for a record-breaking third time) in 1998 until 2004. Randell Kirsch replaced Baker in 2004 to present as falsetto vocalist/guitarist. John Cowsill, an original member of the 1960s pop band The Cowsills, has been a vocalist/keyboardist since 1999.

Some of the changes in The Beach Boys' organization were less formal. They enjoyed a casual collaboration with fellow Southern Californians Jan and Dean. Much to the consternation of other band members, Wilson composed "Surf City" and gave the song, without compensation, to Dean Torrence. Jan and Dean, at the time not nearly as popular as The Beach Boys, recorded the song and scored their first number one single, a year before the Beach Boys finally reached the same milestone. Years later, Torrence happened upon the studio where the Beach Boys were recording their "Beach Boys' Party!" album. He joined in the singing, and can be heard singing harmony in the "Barbara Ann" () cut from that album.

To the surprise and delight of fans around the world, Wilson has mounted several major tours under his own name with a band containing members of The Wondermints and led by former Beach Boys guitarist Jeff Foskett plus other supporting musicians. Their note-perfect live performances of the entire Pet Sounds album earned some of the most glowing concert reviews of Wilson's career, with some commentators calling the shows "the concert of a lifetime". In 2003 and 2004, he and Van Dyke Parks reunited to complete the unfinished sections of Smile, and in 2004 Wilson and his band toured the world performing a live concert version of the album. They then recorded a new studio version of Smile using vintage recording equipment and including sessions at the fabled Sunset Sound Studios in Hollywood, where some of the original recordings were made.

Jardine toured for a while with the Beach Boys Family & Friends (which for legal reasons quickly became Alan Jardine Family & Friends Beach Band, then Al Jardine's Endless Summer Band), featuring his sons Matt and Adam, Wilson's daughters Carnie and Wendy, and Carl's brother-in-law Billy Hinsche, among others. Jardine now tours as the Endless Summer Band which includes his two sons, Hinsche, and several other performers. He also tours with other artists, including Stevie Heger and members of the pop/rock band Tripsitter. Most recently, Brian Wilson and Jardine performed several joint shows in honor of "Pet Sounds'" 40th anniversary and are about to embark on a joint European tour (summer 2007). Litigation continues between Jardine and Love.