Maine - Significance region: Local
| Hichborn, Nathan G., House |
| Higgins Barn |
| High Street Historic District |
| Hinckley Hill Historic District |
| History House |
| Hobbs, Thomas, Jr., House |
| Hodgkins, Ella R., Intermediate School |
| Hog Island-62.23 |
| Hog Island-62.24 |
| Hog Island-62.25 |
| Hog Island-62.29 |
| Holden, Samuel, House |
| Holden Town Hall |
| Holland, Captain, House |
| Holland-Drew House |
| Holmes Cottage |
| Holmes-Crafts Homestead |
| Holmes, Dr. Job, House |
| Holmes Point |
| How, Daniel, House |
| How Houses |
| Hubbard-Cotton Store |
| Hulls Cove High School |
| Hurd, Mary R., House |
| Huse, John E.L., Memorial School |
| Hussey-Littlefield Farm |
| Huston House |
| Hutchins, Frank, House |
| Hutchins House |
| Hutchins, Moses, House |
| Indian River Baptist Church |
| Influence, The |
| Ingalls House |
| Ingraham, Joseph Holt, House |
| Intervale Farm |
| Irish, J. & O., Store |
| Irish Site |
| Isaacson, Philip M. and Deborah N., House |
| Island Falls Opera House |
| Islesboro Free Library |
| Islesford Historical Museum and Blue Ducks Ships Store |
| Jackson, Dr. F. W., House |
| Jacobs Houses and Store |
| Jacobson, Pehr J., House |
| Jarvis, Col. Charles and Mary Ann, Homestead |
| Jay-Niles Memorial Library |
| Jefferson Cattle Pound |
| Jefferson Town House |
| Jellison, Theodore, House |
| Jenkins, Charles W., House |
| Jesup Memorial Library |
| Jewett-Eastman House |
| Johnson, Dennis, Lumber Company Mill |
| Jonathan Fisher Memorial |
| Jonesboro Grange #357 |
| Jonesboro Union Church |
| Jordan, Charles A., House |
| Jordan, F.M., House |
| Jordan School |
| Jordon, Col, Meltiah, House |
| Journal Building |
| Kane, John Innes, Cottage |
| Keen Hall |
| Kennebec County Courthouse |
| Kennebunk High School |
| Kennebunk Historic District |
| Kennebunkport Historic District |
| Kennebunk River Club |
| Kent Burying Ground |
| Kent's Hill School Historic District |
| Kezar Falls Circulating Library |
| Kineo Cottage Row Historic District |
| Kinsley, Martin, House |
| Knight-Corey House |
| Knowlton, Ebenezer, House |
| Kora Temple |
| Kresge Building |
| Kromberg Barn |
| Lakeside Grange #63 |
| Lamb Block |
| Lancaster Block |
| Land's End Historic District |
| Larsson-Noak Historic District |
| Lawrence Library |
| Leavitt, A. B., House |
| Leavitt, James, House |
| Lee, Jesse, Church |
| Lermond Mill |
| Lewiston City Hall |
| Lewiston Commercial Historic District |
| Lewiston Public Library |
| Lewiston Trust and Safe Deposit Company |
| Libby-Hill Block |
| Libby's Colonial Tea Room |
| Liberty Hall |
| Limerick Upper Village Historic District |
| Limington Academy |
| Limington Historic District |
| Lincoln Park |
| Lincoln School |
Data from United States Park Service and Wikidata
