The singer in the band behind such hits as the Burt Bacharach-penned ballad Make it Easy on Yourself and The Sun Ain't Gonna Shine Anymore passed away at his home in Los Angeles after a six-month fight with disease.
Walker, who along with Scott Engel and Al Schneider made up the sixties supergroup, sang lead vocals and played guitar, taking the band to worldwide fame and touring with the likes of Jimi Hendrix, and Cat Stevens.
A statement on his website said simply: "It is with our deepest sadness that we report that Mr John Walker passed away in his Los Angeles area home on May 7, 2011. He was a beloved husband, brother, father, grandfather, friend and artiste."
The Walker Brothers was founded in 1964 but after a slew of successes, the trio split in 1967 following internal tensions that had sent fellow band member Engel, by then known as Scott Walker into suicidal depression.
Duran Duran star Simon le Bon paid tribute to the singer on Twitter, tweeting "John Walker, founder member of the Walker Bros. died. I'm hearing No Regrets as I type."