Iowa - Significance region: Local
| 100 Block of West Broadway Historic District |
| Abraham Lincoln High School |
| Abraham Lincoln Statue and Park |
| Acadian Manor Historic District |
| Adair County Courthouse |
| Adair County Democrat-Adair County Free Press Building |
| Adams County Jail |
| Adams-Higgins House |
| Adams, Walker, House |
| Adel Bridge |
| Adel Public Square Historic District |
| Adler, E. P., House |
| Administration Building, U.S. Naval Air Station Ottumwa |
| Agassiz School |
| Agriculture Hall |
| Ainsworth, William W. and Elizabeth J., House |
| Akron Opera House |
| Albertson and Company-Rocklin Manufacturing Company |
| Albertus Building |
| Albia Square and Central Commercial Historic District |
| Albright, Henry D. and Juliana (Wortz), House |
| Algona Junior and Senior High School Building and High School Building Annex |
| Alhambra Apartments |
| Allamakee County Court House |
| Allee, Jesse J. and Mary F., House |
| Allen, G. W. S., House |
| Allen House |
| Allen, James, Stone Barn |
| Allen, Robert and Catharine (Ripley), House |
| All Saints Catholic Church |
| Alumni Hall |
| Ambler, Henry, House |
| Ambrose Hall |
| American Commercial and Savings Bank |
| American House |
| American Legion Memorial Building |
| American Republic Insurance Company Headquarters Building |
| American Telephone & Telegraph Co. Bldg. |
| Ames High School |
| Ames Main Street Historic District |
| Anamosa Main Street Historic District |
| Anderson, D. H., Building |
| Anderson, D. H., House |
| Andrews, Josiah, House |
| Andrus, A. J., Duplex |
| Ankeny Building |
| Anthony, Horace, House |
| Antioch School |
| Antlers Hotel |
| Appanoose County Courthouse |
| Appanoose County Sheriff's House and Jail |
| Apperson-Iowa Motor Car Company Building |
| Architecture of Henry K. Holsman Historic Campus District |
| Argonne Building |
| Argyle Flats |
| Armour Creameries Poultry House |
| Armstrong, George and Susan Guiberson, House |
| Armstrong, Robert and Esther, House |
| Arthur, Thomas, House |
| Ashby, Atchison A., House |
| Ashby Manor Historic District |
| Ash Park Historic District |
| Ashton, Ned, House |
| Aspen Grove Cemetery Historic District |
| Atchison, Topeka and Santa Fe Passenger and Freight Complex Historic District |
| Atlantic High School |
| Audobon County Court House |
| Audubon County Courthouse |
| Audubon County Home Historic District |
| Aunty Green Hotel |
| Ausadie Building |
| Averill, A. T., House |
| Averill, Glenn M. and Edith, House |
| Avery Theater, The |
| Ayrshire Apartments |
| Bailey, George A. and Mary Tinkel, House |
| Bailey, William H. and Alice, House |
| Baird, E. J., House |
| Baker, C. H., Double House |
| Baker-Devotie-Hollingsworth Block |
| Ballard, John W., House |
| Ball, Dr. J. O. and Catherine, House |
| Ball-Waterman House |
| Ball, W. C., House |
| Bandshell Park Historic District |
| Bangs, John and Lavina, House |
| Bank of Sumner |
| Banta, J. V., House |
| Baptist Church |
| Barkley, Alonzo J. and Flora, House |
| Barrows, Edward S., House |
| Bartlett, Walter M., Double House |
| Bassnett-Nickerson House |
| Bates Park Historic District |
| Bauman, Augustus and Elizabeth (Huntsberger), House |
| Baum, William A. and Etta, Cottage |
| B Avenue NE Historic District |
| Baxter, H.A., Coal Company Historic District |
| Bay Settlement Church and Monument |
| Beach School |
Data from United States Park Service and Wikidata
