State Route 79 is a 117-mile-long (188 km) route that extends northeastward from Birmingham to the Tennessee state line. Prior to the completion of Interstate 65, SR-79 was the southern part of the route that connected Birmingham and Huntsville.

The southern terminus of SR-79 is at the interchange of Tallapoosa Street with Interstate 20/Interstate 59 (Exit 128) near Birmingham-Shuttlesworth International Airport. Prior to the completion of I-20/I-59, the terminus of SR-79 was at its junction with U.S. Highway 31, U.S. Highway 78 and U.S. Highway 280 at the intersection of 8th Avenue North and 24th Street in downtown Birmingham.

The highway is four-laned from Interstate 20/59 to a gap in Sand Mountain, where it passes under two Alabama Power transmission lines, one coming from the Miller Steam Plant. After leaving Tarrant, there is little retail development along Highway 79 in Jefferson County, although Wal-Mart plans to build a Wal-Mart Supercenter just south of Pinson.

After leaving Birmingham and Jefferson County, the route of SR-79 takes it through rural areas of Blount County, Marshall County and Jackson County and is largely a two-lane highway. Due to population growth in the area, there are long range plans to widen SR-79 to four lanes into southwestern Blount County. Aside from Birmingham, the only cities with a population exceeding 5,000 that SR-79 passes through are Guntersville and Scottsboro.

North of Scottsboro, SR-79 leads toward Winchester, Tennessee. North of the Tennessee state line, the route is numbered State Route 16.