Its western terminus is at a T-intersection with SR 220 about four miles (6.4 km) southwest of Waverly, and its eastern terminus is at a T-intersection with SR 104 approximately two and a half miles (4.0 km) southwest of Waverly.

Existing entirely within Pike County's Pee Pee Township, SR 551 follows the south shore of Lake White, while SR 552 follows the north shore.

Lake White State Park is located near SR 551's western terminus.

Abutted by forest on the south side for most of its length, SR 551 starts out in a southerly direction, then hooks around the west end of Lake White, bending to the northeast.

The highway then travels in an inverted "U", curving east and then to the south and southeast.