East of US 29, US 33 reduces to two lanes and enters Orange County. The highway has a short concurrency with SR 20 (Constitution Highway) through Barboursville, where both highways pass under the Norfolk Southern Railway's Washington District rail line. US 33 passes through a gap in the Southwest Mountains before reaching Gordonsville. At the town limit, the U.S. Highway has an intersection with SR 231 (Blue Ridge Turnpike). US 33 and SR 231 run together a short distance east to the Gordonsville Roundabout, where SR 231 heads southwest as Gordon Avenue toward Cismont and US 33 becomes concurrent with US 15 (James Madison Highway) along Main Street. The two highways pass the Exchange Hotel at their underpass of the Washington Subdivision, the Charlottesville–Orange rail line owned by the Buckingham Branch Railroad. At the southern edge of downtown Gordonsville, US 33 and US 15 leave Main Street and veer onto Martinsburg Avenue, which follows CSX's Piedmont Subdivision to the southern limit of Gordonsville, where the highways enter Louisa County.