- Kamenka, Hippolyte18
- Kaplan, Robert1
- Katz, S. Walker1
- Kavy and Kavovitt15
- Kelly and Gruzen4
- Kessler, S.J.1
- Kibel, Henry1
- Kiesler, Frederick J.1
- Kiff, Colean, Voss and Souder1
- Knoll, Alvin D.2
- Kokkins and Lyras39
- Kokkins, John M.20
- Kornblath, Hanle, and Liebman3
- Kornblath, Leo15
- Kraus, David10
- Kreymborg, Charles11
- Lamb, Thomas W.1
- Lapidus, Morris3
- Larkin, Edward L.5
- Larkin, John A.5
- Leff and Birnbaum3
- Leff, Ralph2
- Leicht, Walter G.1
- Lench, Charles H.2
- Lescaze, William24
- Levy, Emilio1
- Levy, Leon2
- Levy, Lionel6
- Levy, Sampson1
- Lewis, Albert W.4
- Lewis, Jules1
- Lewis, Robert L.1
- Liebman, Liebman and Associates6
- Lilien, Clarence16
- Lilien, H. Herbert33
- Lion, Henry S.1
- Lippman, Herbert1
- Ludlow and Peabody2
- Lyons, Robert T.5
- Lyras and Anaya2
- Lyras, Galvin and Anaya17
- Maggio, Nevio3
- Maggiora, Nevio4
- Margon and Holder2
- Margon, Irving2
- Martine, Joseph1
- Maxon, Sells, and Ficke12
- Maxon-Feld5
- Mayer and Whittlesey11
- Mayer, Whittlesey, and Glass16
- Mayers, J. Lewis6
- Maynicke, Robert1
- Mayper, Victor9
- McCrea, A. Wallace1
- McKim, Mead and White15
- McNamara, John J.1
- Meyers, Charles B.2
- Miller and Goldhammer8
- Miller, George G.22
- Miller, Reuben1