State Route 550 is an east–west state highway in the southeastern portion of the U.S. state of Ohio. The western terminus of SR 550 is at an interchange with U.S. Route 33 (US 33) just north of the city limits of Athens, immediately south of the southern terminus of SR 13. The eastern terminus of SR 550 is at an intersection with SR 7 just west of Marietta.

U.S. Route 33 (US 33) is a United States Numbered Highway running from near Elkhart, Indiana, to Richmond, Virginia. Within the state of Ohio, it is a predominantly southeast–northwest highway running from west of Willshire before crossing over into West Virginia via the Ravenswood Bridge over the Ohio River. The route runs through largely rural territory throughout most of the state's west-central, central, and southeastern regions, although it also passes through large portions of downtown Columbus.