John R. Hamilton was a nineteenth-century English and American architect, active between 1840 and 1870. Hamilton had a significant practice in his native England before moving to North America in 1850. Between 1852 and 1859, in Cincinnati, Ohio, Hamilton's business thrived, with a long list of private homes, churches, and several major public buildings. He then moved to New York City, can be found in the American south as a traveling graphic journalist during and after the Civil War, and was again practicing architecture from New York in 1870.