Mercier—Morland
- Mercier, Alfred
- Merrill, James Cushing
- Metcalf, W. G.
- Metcalfe, Samuel L.
- Mettauer, John Peter
- Metz, Abraham
- Michel, Charles Eugene
- Michel, William Middleton
- Michener, Ezra
- Middleton, Peter
- Miles, Albert Baldwin
- Miles, Francis Turquand
- Miles, Manly
- Millard, Perry H.
- Miller, Edward
- Miller, Henry
- Miller, John
- Miller, Patience, see Doolittle, Benjamin
- Miller, Thomas
- Miltenberger, George Warner
- Miner, Julius Francis
- Miner, Thomas
- Minor, Thomas Chalmers
- Minot, Charles Sedgwick
- Minot, Francis
- Mitchell, Ammi Ruhamah
- Mitchell, Giles Sandy
- Mitchell, John
- Mitchell, John Kearsley
- Mitchell, Silas Weir
- Mitchell, Thomas Duché
- Mitchill, Samuel Latham
- Moher, Thomas J.
- Monette, John Wesley
- Monroe, Hollis
- Monroe, Nahum Parker
- Montgomery, Frank Hugh
- Moore, Edward Mott
- Moore, James Edward
- Moore, John
- Moore, Samuel Preston
- Morehouse, George Read
- Morgan, Ethelbert Carroll
- Morgan, John
- Morland, William Wallace
Morrill—Nelson
- Morrill, David Lawrence
- Morrin, Joseph
- Morris, Caspar
- Morris, John
- Morrison, Robert Brown
- Morrow, Prince Albert
- Morton, Samuel George
- Morton, William Thomas Green
- Moses, Thomas Freeman
- Mosher, Jacob Simmons
- Mott, Alexander Brown
- Mott, Valentine (1785–1865)
- Mott, Valentine (1822–1854), see Mott, Valentine (1785–1865)
- Mott, Valentine (1852–1918), see Mott, Valentine (1785–1865)
- Moultrie, James
- Mower, Thomas Gardner
- Moyer, Isaac Shoemaker
- Muir, Samuel Allan
- Muir, William Scott
- Mumford, James Gregory
- Mundé, Paul Fortunatus
- Munn, Edwin George
- Munn, William Phipps
- Munro, John Cummings
- Munson, Eneas
- Münsterberg, Hugo
- Murdoch, James Bissett
- Murdoch, Russell
- Murphy, John Alexander
- Murphy, John Benjamin
- Murphy, Patrick Livingston
- Murray Robert
- Murray, Robert Drake
- Musser, John Herr
- Mussey, Reuben Dimond
- Mussey, William Heberden
- Mütter, Thomas Dent
- Myers, Albert William
- Nancréde, Joseph Guérard
- Neill, Henry
- Neill, John
- Neilson, William Johnston
- Nelson, David
- Nelson, Robert
- Nelson, Wolfred (1792–1863)
- Nelson, Wolfred (1846–1913)
Newberry—Page
- Newberry, John Strong
- Newton, Robert Safford (1818–1881)
- Newton, Robert Safford (1855–?), see Newton, Robert Safford (1818–1881)
- Nichols, Charles Henry
- Nichols, James Robinson
- Nickles, Samuel
- Noeggerath, Emil Oscar Jacob Bruno
- Norcom, William Augustus Blount
- Norris, George Washington
- Norris, William Fisher
- North, Elisha
- Norton, Rupert
- Norwood, Joseph Granville
- Nott, Josiah Clark
- Nourse, Amos
- Noyes, Henry Dewey
- Noyes, James Fanning
- O'Callaghan, Edmund Bailey
- O'Connell, Joseph John
- O'Dwyer, Joseph
- Ogden, William Winslow
- O’Hagan, Charles James
- Ohlmacher, Albert Philip
- Oliver, Charles Augustus
- Oliver, Fitch Edward
- Oliver, George Powell, see Oliver, Charles Augustus
- Oliver, James
- Oppenheim, Nathan
- Ordronaux, John
- O'Reilly, Robert Maitland
- Orton, George Turner
- Otis, Fessenden Nott
- Otis, George Alexander
- Ott, Isaac
- Otto, John Conrad
- Ouchterlony, John Ardid
- Ouvrière, see Pascalis-Ouvrière, Felix A.
- Owen, David Dale
- Owen, William
- Owen, William Otway
- Packard, Frederick A
- Packard, John Hooker
- Page, Alexander Crawford
- Page, Benjamin (1770–1844)
- Page, Benjamin (?–1829), see Page, Benjamin (1770–1844)
Paine—Pepper
- Paine, Martyn
- Pallen, Montrose Anderson
- Pallen, Moses Montrose
- Palmer, Alonzo Benjamin
- Palmer, James Croxall
- Palmer, John Williamson
- Pancoast, Joseph
- Pancoast, Seth
- Pancoast, William Henry
- Park, John Gray
- Park, Roswell
- Parker, Daniel McNeil
- Parker, Edward Hazen
- Parker, Willard
- Parker, William W.
- Parkes, Charles Theodore
- Parkhill, Clayton
- Parkman, George, see Webster, John White
- Parrish, Isaac
- Parrish, Joseph (1779–1840)
- Parrish, Joseph (1818–1891)
- Parry, Charles Christopher
- Parry, John Stubbs
- Parsons, Ralph Lyman
- Parsons, Usher
- Parvin, Theophilus
- Pascalis-Ouvrière, Felix A.
- Patterson, David Nelson
- Patterson, Henry Stuart
- Patterson, Richard John
- Patterson, Robert Maskell
- Pattison, Granville Sharp
- Peabody, George Livingston
- Peabody, James H.
- Peaslee, Edmund Randolph
- Peaslee, Edward H., see Peaslee, Edmund Randolph
- Peck, William Dandridge
- Peirce, David
- Peirson, Abel Lawrence
- Pendleton, Lewis Warrington
- Pennock, Caspar Wistar
- Penrose, Richard Alexander Fullerton
- Pepper, George
- Pepper, William (1810–1864)
- Pepper, William (1843–1898)