Most of the route is a rural two-lane highway and passes through both farmland and residential properties.

The route heads northwest as a two-lane highway crossing over a railroad track.

The road passes through residential properties, before turning northeast towards downtown Bluffton.

As the route heads southeast it passes over the railroad track again, followed by a curve due east.

East of Bluffton the route passes through farmland and has an intersection with SR 235, in rural Hancock County.

The highway passes through farmland and begins a concurrency with SR 37, on the south side of Mount Blanchard.

SR 103 continues northeast concurrent with US 23, passing residential properties on its way to downtown.

In downtown the route turns due south, passing commercial properties and having an intersection with SR 602.

The route heads east through farmland, having an intersection with SR 39, before turning due north in rural Crawford County.

SR 103 heads east as the county line, before turning due north towards Willard.

Tiffin Street heads east through residential properties and passing under a railroad with a low 13 ft 2-in clearance, before an intersection with SR 99.

US 25 ran concurrent with I–75, leaving SR 103 to replace US 103 through the south side of Bluffton.

[13][14] By 1969, its eastern terminus was extended to its current location, replacing the now defunct route numbers 194 and 298.