Who sings the song?

Lots of people have. State Song of Georgia, most commonly sung by Ray Charles.

"Georgia on My Mind" is a 1930 song written by Hoagy Carmichael and Stuart Gorrell and first recorded that year. It has often been associated with Ray Charles, a native of the U.S. state of Georgia who recorded it for his 1960 album The Genius Hits the Road. In 1979, the State of Georgia designated it the official state song.