State Route 90 (SR 90) is a state highway that runs southeast-to-northwest through portions of Atkinson, Coffee, Irwin, Ben Hill, Turner, Wilcox, Crisp, Dooly, Macon, Taylor, and Talbot counties from southern to west-central Georgia. The route runs from its southeastern terminus at US 82 and SR 520 in Willacoochee to its northwestern terminus at US 80, SR 22, and SR 41 in Talbotton.

The route runs northwest from Willacoochee in Atkinson County, through the southwestern corner of Coffee County, to Ocilla in Irwin County. Heading north, the route heads through Fitzgerald in Ben Hill County, before turning first northwest again, then west, to Rebecca in Turner County. Still in Turner County, the route then continues first west, then turns back north and then west again, and forms a short stretch of county line to Wilcox County before running west through the very southwestern corner of Wilcox County, then turning northwest and on into Cordele in Crisp County, crossing I-75 just before going through Cordele.

SR 90 then heads north through Vienna, then northwest through Byromville, both in Crisp County, before heading into the Macon County municipalities of Montezuma and Oglethorpe. Still heading northwest the route continues into and through the southern portion of Taylor County, and travels through Junction City in Talbot County, before reaching its northwestern terminus in Talbotton.