Clarence Carter -- the legendary blind soul singer behind countless R&B classics -- has died at 90.

Rodney Hall, president of FAME Studios in Alabama, confirmed the news to Rolling Stone ... after Hall spoke with the family of singer Candi Staton, Carter's ex-wife, who said the icon passed away Thursday.

Carter had recently been diagnosed with stage 4 prostate cancer and was also battling pneumonia and sepsis.

The soul legend spent more than six decades in music, becoming known for his unmistakable baritone voice and steady run of R&B hits throughout the late '60s and '70s.

Among his biggest tracks were "Strokin'," "Slip Away," "Too Weak to Fight" and "Patches" -- the latter earning him a Grammy nomination for Best R&B Song in 1971.

Carter was 90.

RIP