The first artist to use Auto Tune for a distinct effect (rather than just pitch correction) was Cher in her 1998 single Believe. Only a year after Auto Tune was released.
T-Pain absolutely was the one who popularized it through. To the point that among the general public "Auto Tune" is associated more with "electronic voice effects" than it is with "pitch correction."
T-Pain absolutely was the one who popularized it through. To the point that among the general public "Auto Tune" is associated more with "electronic voice effects" than it is with "pitch correction."