Wisconsin - Significance region: Local
| Indian Point Site |
| Ingalsbe, Adolphus and Sarah, House |
| Iowa County Courthouse |
| Iowa Street Historic District |
| IRIS (Shipwreck) |
| Irving Church Historic District |
| Isermann, Anthony and Caroline, House |
| Isermann, Frank and Jane, House |
| Island Lake Camp |
| Island of Happy Days |
| Island Village Site |
| Island Woolen Company Office Building |
| Italian Workmen's Club |
| Iverson-Johnson House |
| Jabodon |
| Jackman Building |
| Jackson House |
| Jacksonport Wharf Archeological District |
| Jacobson House and Mill Site |
| Jahn, William F., Farmstead |
| James, Samuel D., House |
| Janesville Cotton Mill |
| Janesville High School |
| Janesville Pumping Station |
| Jefferson Avenue Historic District |
| Jefferson Fire Station |
| Jefferson High School |
| Jenifer-Spaight Historic District |
| Jenkins, Halbert D., House |
| Jennings, Ellis, House |
| Jensen, J. L., House |
| Jensen, Matt and Lena, House |
| Jensen, Tollef, House |
| Jensvold, Gulbrand and Bertha, House |
| Johnson, Albin, Log House |
| Johnson, A.P., House |
| Johnson, Dr. Samuel C., House |
| Johnson, Isabel and Orrin, House |
| Johnson, John, Saloon |
| Johnson, Matt, Log House |
| Johnson, Nels and Nellie, House |
| Johnson, Peter, House |
| Johnston Hall |
| Joint Brussels and Garner Dristrict School Number One |
| Jollywood |
| Jones, David J. and Maggie, House |
| Jones-Hill House |
| Jones, Huff, House |
| Jones, John A. and Maggie, House |
| Jones, John H., House |
| Jones, Robert O., House |
| Jones, Samuel S., Cobblestone House |
| Joseph Schiltz Company Brewery Complex |
| Juneau County Courthouse |
| Juneau Highlands Residential Historic District |
| Jung Carriage Factory |
| Jung Shoe Manufacturing Company Factory |
| Kaiser Lumber Company Office |
| Kaiser's |
| Kalvelage, Joseph B., House |
| Kane, Sanford R., House |
| Kane Street Historic District |
| Kayser, Adolph H., House |
| Keefe, Franklin E. and Eva E., House |
| Kegel's Inn |
| Kekoskee Archeological District |
| Kelliher, Michael, House |
| Kellogg Public Library and Neville Public Museum |
| Kell, William H., House |
| Kemp, John and Margarethe, Cabin |
| Kendall-Blankenburg House |
| Kendall Cabinet Shop |
| Kendalls Depot |
| Kenosha Elks Club |
| Kenosha Light Station |
| Kenosha North Pierhead Light |
| Kenwood Park-Prospect Hill Historic District |
| Kenyon, A. L., House |
| Kerwin, Judge J. C., House |
| Ketchum, Daniel and Caltherine, Cobblestone House |
| Ketter, Frederick, Warehouse |
| Kewaunee County Sheriff's Residence and Jail |
| Kewaunee Pierhead Lighthouse |
| Kewaunee Post Office |
| Kilbourn Avenue Row House Historic District |
| Kilbourn Masonic Temple |
| Kilbourn Public Library |
| Kimball, Alanson M., House |
| Kimberly Point Park Lighthouse |
| Kingsley Bend Mound Group |
| King Street Arcade |
| Kinney, Patrick and Margaret, House |
| Kinnickinnic Church |
| Kinnickinnic River Parkway |
| Kissel, George A., House |
| Kissel, Louis, House |
| Kissel, Otto P., House |
| Kissel's Addition Historic District |
| Kissel's Wheelock Addition Historic District |
| Kissel, William L., House |
Data from United States Park Service and Wikidata
