John Cowsill (b. March 2, 1956 in Rhode Island) is an American musician, best known for his work as a singer and drummer with his siblings` band, The Cowsills. He is currently a drummer and vocalist for the current The Beach Boys touring band, which features original Beach Boys Mike Love and Bruce Johnston. He has also played keyboards for the "Beach Boys Band", and according to the bands` website, he does Al Jardine`s and the late Carl Wilson`s vocal parts.  He also has performed and recorded with Jan and Dean.
In the early 1980s, he was a member of the one hit wonder band Tommy Tutone, and he plays the drums and sings back-up vocals on the band`s hit, 867-5309/Jenny although he did not appear in the video.
For a time, he was part of Dwight Twilley`s band, as was his sister Susan Cowsill.
In 2003, he married Vicki Peterson of the The Bangles.
He has appeared as an actor on Full House and General Hospital.
John Cowsill began playing with the Beach Boys on the keyboard in 2000. He recently took over on the drums in 2008 for the Beach Boys lead by Mike Love and Bruce Johnston.  John`s solos for the concerts include, "Help Me Rhonda," "Would`t It Be Nice," "I Can Hear Music," and "Darlin`."