California - Area of significance: Architecture
| House at 1331-1335 Scott Street |
| House at 1360 Lida Street |
| House at 1487 Loma Vista Street |
| House at 380 W. Del Mar Blvd. |
| House at 530 S. Marengo Avenue |
| House at 574 Bellefontaine St. |
| House at 584 Page Street |
| House at 674 Elliot Drive |
| Howard Motor Company Building |
| Howe, Edward P., Jr., House |
| Howell House |
| Howe-Waffle House and Carriage House |
| Hoyt-Scott House |
| Hubbard-Upson House |
| Humboldt Bay Life-Saving Station |
| Humboldt Bay Woolen Mill |
| Hunt Center and Library |
| Hunter-Dulin Building |
| Hunters Point Commercial Drydock Historic District |
| Hunt House |
| Huntington Beach Municipal Pier |
| Huntington Beach Public Library on Triangle Park |
| Hutton, Warner, House |
| Hyde House |
| Hyde, Jeremiah D. and Mary, House |
| Immanuel Evangelical Lutheran Church of Alameda |
| Independence Hall |
| Independent Order of Odd Fellows Building |
| Inspiration Heights Historic District |
| Institute of Geophysics and Planetary Physics |
| Integratron |
| Inyo County Courthouse |
| Ione City Centenary Church |
| I.O.O.F. Building |
| I.O.O.F. Hall |
| Irvine Bean and Growers Association Building |
| Irvine Blacksmith Shop |
| Irvine Park |
| Irving, Washington, Branch |
| Isleton Chinese and Japanese Commercial Districts |
| Iverson House |
| Jackson Brewing Company |
| Jackson, Helen Hunt, Branch |
| Jackson Square Historic District |
| Jacoby Building |
| Janssen, E., Building |
| Janssens-Orella-Birk Building |
| Jardinette Apartments |
| Jarvis, Benjamin, House |
| Jastro Building |
| Jefferson Branch |
| Jefferson, Thomas, Elementary School |
| Jefferson, Thomas, School |
| Jeffers, Robinson, House |
| Jensen, Cornelius, Ranch |
| Jessie Street Substation |
| John Muir National Historic Site |
| Johnson, Hugh Edgar, House |
| Johnson, J. Neely, House |
| Johnson-Taylor Ranch Headquarters |
| Johnston, Darius David, House |
| Johnston, James, House |
| Jones, A. Quincy, Barn |
| Judah, Theodore, School |
| Judge Lee House |
| Judson Studios |
| Kaehler-Rector House |
| Kahn's Department Store |
| Karasik House |
| Kearney, M. Theo, Park and Mansion |
| Kee House |
| Kee, Sam, Laundry Building |
| Kelso Depot, Restaurant and Employees Hotel |
| Kelton Apartments |
| Kenaston House |
| Kennedy Mine Historic District |
| Kerckoff Building and Annex |
| Kern Branch, Beale Memorial Library |
| Ketchum, Billy, House |
| Keyes Bungalow |
| Key, George, Ranch |
| Killefer, Lydia D., School |
| Killingsworth, Brady, & Smith |
| Kimberly Crest |
| Kindel Building |
| Kindler, Paul, House |
| King City Joint Union High School Auditorium |
| King Edward Hotel |
| Kingen Hotel |
| KING PHILIP (ship) and REPORTER (schooner) Shipwreck Site |
| Kings County Courthouse |
| Kinsey, Martha, House |
| Kleiser, James, House |
| Knights Ferry |
| Knipp and Stengel Ranch Barn |
| Kocher-Samson Building |
| Koerner House |
| Kohl Mansion |
| Koshland House |
| Kosy Knook Court |
Data from United States Park Service and Wikidata
