The highway's southern terminus is at a T-intersection with State Route 643 approximately 2 miles (3.2 km) north of Baltic.

Established in 1937, SR 557 runs exclusively within Holmes County.

The highway passes through Charm, before turning due west.

[8] SR 557 has its lowest traffic counts; within the 2013 ODOT survey, the road is listed with an average annual daily traffic(AADT) of 920 vehicles on a section of highway between the southern terminus and Holmes County Road 600 (CR 600).

ODOT figured that the peak traffic levels were present on the section that is between CR 600 and Township Road 154 (T–154), where 3,360 vehicles used the highway daily.