Rockbridge is an unincorporated community and census-designated place in eastern Good Hope Township, Hocking County, Ohio, United States. Although it is unincorporated, it has a post office, with the ZIP code of 43149. It is located at the interchange of U.S. Route 33 and State Route 374, between Logan and Lancaster. As of the 2010 census the population of the CDP was 182.The area around Rockbridge contains many tourist destinations, including portions of the Hocking Hills State Park System and Clear Creek, part of the Columbus Metro Parks system.A post office called Rockbridge has been in operation since 1863. The community is named after a natural bridge that is located to the east in the Rockbridge State Nature Preserve. The bridge is formed of sandstone and stretches more than 100 feet long and 10 to 20 feet wide over a ravine on a small tributary of the Hocking River.