Rock United Presbyterian Church is a historic Presbyterian church located at Elkton, Cecil County, Maryland. It is a rectangular building of uncoursed rubble stone construction, three bays wide by three deep, with a steeply pitched slate-clad gable roof. It was originally constructed in 1761, and remodeled to its current Victorian Gothic influenced appearance in 1872 and 1900. Also on the property is a 1 1/2-story, stone Session House originally constructed in 1762 and a modern white stucco Church House constructed in 1953. The church is significant due to its association with the early Scotch-Irish immigrants to Maryland. It was listed on the National Register of Historic Places in 1983.