Maine - Criteria: C (architecture/engineering)
| Bourne Mansion |
| Bowman-Carney House |
| Boynton High School, Former |
| Boynton Street Historic District |
| Brave Boat Harbor Farm |
| Bray House |
| Breakwater, The |
| Breckinridge, Isabella, House |
| Brewer, Henrietta, House |
| Brewer High School |
| Brewer, John N.M., House |
| Brewster, Royal, House |
| Brickett Place |
| Brick School |
| Brick School House |
| Bridge Academy |
| Bridgewater Town Hall and Jail |
| Briggs, William, Homestead |
| Broad Street Historic District |
| Broadway Historic District |
| Brooklin IOOF Hall |
| Brown, C. A., Cottage |
| Brown, J. B., Memorial Block |
| Brown Memorial Library |
| Brown-Pilsbury Double House |
| Browns Head Light Station |
| Brunswick Commercial Historic District |
| Bryant, Charles G., Double House |
| Buck Memorial Library |
| Bucknam House |
| Bucknam, Samuel, House |
| Bucksport Railroad Station |
| Burgess House |
| Burnell Tavern |
| Burnham Tavern |
| Burnt Coat Harbor Light Station |
| Burton, Benjamin, Garrison Site |
| Bussey, Louis I., School |
| Butler, A. B., House |
| Butterfield-Sampson House |
| Calais Free Library |
| Calais Historic District |
| Calais Residential Historic District |
| Camden Great Fire Historic District |
| Camden Opera House Block |
| Camden Yacht Club |
| Campbell, Col, Samuel, House |
| Campbell, David W., House |
| Campbell, Frank, House |
| Camp Hammond |
| Canadian Pacific Railway Depot, Greenville Junction, Maine |
| Cape Arundel Golf Club |
| Cape Arundel Summer Colony Historic District |
| Capitol Complex Historic District |
| Capitol Park |
| Carleton, Moses, House |
| Carleton, Robert, House |
| Carrabasset Inn |
| Carriage Paths, Bridges and Gatehouses |
| Carr, Robert P., House |
| Carver Memorial Library |
| Cary Library |
| Castine Historic District |
| Caswell Public Library (Former) |
| Cate House |
| Cathance Water Tower |
| Cathedral of the Immaculate Conception |
| Center Meeting House and Common |
| Central Congregational Church |
| Central Parish Church |
| Centre Street Congregational Church |
| Chaloner House |
| Chandler Store |
| Chapman-Hall House |
| Chapman, Leonard Bond, House |
| Chase, Capt. Josiah E., Octagon House |
| Chase, Hezekiah, House |
| Chase, Squire, House |
| Cherryfield Academy |
| Cherryfield Historic District |
| Chestnut Street Historic District |
| Chestnut Street Methodist Church |
| Chesuncook Village |
| Children's Hospital |
| China Village Historic District |
| Christ Church |
| Christ Episcopal Church |
| Churchill Bridge |
| Church of Our Father |
| Church of the Advent |
| Church of the New Jerusalem |
| Church Street Historic District |
| Clapp, Charles Q., Block |
| Clapp, Charles Q., House |
| Claremont Hotel |
| Clark, Edmund and Rachel, Homestead |
| Clase, Nicholas P., House |
| Cleaveland, Parker, House |
| Cleaves, Benjamin, House |
| Cleftstone |
Data from United States Park Service and Wikidata
