Its western terminus is on U.S. Route 27 in Oxford at the intersection of SR 732.

SR 73’s eastern terminus is in Portsmouth at US 23; this is also the southern terminus of SR 104, and the two state routes run concurrently for over 6 miles (9.7 km) from this point north.

Once SR 73 enters Scioto County, it is designated as the Scenic Scioto Heritage Trail by the Ohio Department of Transportation.

[2] In combination with SR 32, SR 73's easternmost 31 miles (50 km) are part of the quickest route between Cincinnati and Portsmouth.

The portion of SR 73 between Interstate 75 and SR 741 in Springboro is designated as the "Officer Bill Johnson Memorial Highway",[3] in honor of William L. "Bill" Johnson, a 48-year-old, eight-year veteran of the Springboro Police Department who was struck and killed by a vehicle around 12:30 a.m. on June 27, 1983 while outside his cruiser on SR 73, investigating two people walking in the roadway.