Duncan House or Duncan Farm may refer to:
In Australia Duncan House (Castlecrag), a heritage-listed house in Sydney suburb of Castlerag
In the United States (by state then city) Father William Duncan House, Metlakatla, AK, listed on the NRHP in Alaska Duncan House (Harrison, Arkansas), listed on the NRHP in Arkansas Hersey-Duncan House, Wilmington, DE, listed on the NRHP in Delaware Harry C. Duncan House, Tavarcs, FL, listed on the NRHP in Florida Horace Duncan House, Lake City, FL, listed on the NRHP in Florida Strange-Duncan House, Carnesville, GA, listed on the NRHP in Georgia Duncan Farm (Grafton, Illinois), listed on the NRHP in Illinois Smith-Duncan House and Eastman Barn, Grafton, IL, listed on the NRHP in Illinois Joseph Duncan House, Jacksonville, IL, listed on the NRHP in Illinois Duncan Manor, Towanda, IL, listed on the NRHP in Illinois Trippett-Glaze-Duncan Farm, Patoka, IN, listed on the NRHP in Indiana John M. Duncan House, Winterset, IA, listed on the NRHP in Iowa Duncan-Duitsman Farm Historic District, George, IA, listed on the NRHP in Iowa Charles Duncan House, Lawrence, KS, listed on the NRHP in Kansas Henry Duncan House, Bloomfield, KY, listed on the NRHP in Kentucky Bradshaw-Duncan House, Crestwood, KY, listed on the NRHP in Kentucky Duncan House (Franklin, Kentucky), listed on the NRHP in Simpson County, Kentucky Duncan House (Greenville, Kentucky), contributing building in South Cherry Street Historic District J. W. Duncan House, Nicholasville, KY, listed on the NRHP in Kentucky Stuart E. and Annie L. Duncan Estate, Louisville, KY, listed on the NRHP in Kentucky Duncan House (Springfield, Kentucky), listed on the NRHP in Washington County, Kentucky Beecher H. Duncan Farm, Westfield, ME, listed on the NRHP in Maine Duncan House, Beaufort, NC, listed on the NRHP in North Carolina Andrews-Duncan House, Raleigh, NC, listed on the NRHP in North Carolina Robert P. Duncan House, Bexley, OH, listed on the NRHP in Ohio Donald C. Duncan House, a Frank Lloyd Wright-designed house in Polymath Park in Acme, Pennsylvania Bishop William Wallace Duncan House, Spartanburg, SC, listed on the NRHP in South Carolina Wright-Henderson-Duncan House, Granbury, TX, listed on the NRHP in Texas Duncan, John, Harriet, and Eliza Jennett, House, Centerville, UT, listed on the NRHP in Utah Holland-Duncan House, Moneta, VA, listed on the NRHP in Virginia