- O'Gorman, William, J. 1
- O'Hara, Geoffrey, 1882-1967 1
- O'Mara, Herbert1
- O'hara, Fiske, 1878-1945 (composer/lyricist)1
- Oesten, Theodore1
- Olcott, George F. 1
- Olds-Haight, Nettie 1
- Oliver, James B. (composer)1
- Olman, Abe 1
- Openshaw, John (composer)1
- Orlob, Harold F., 1885- 1
- Osborne, Nat, 1878-1954 1
- Osborne, Nat, 1878-1954 (composer)1
- Owen, Anita 1
- Paine, Della Williams 1
- Paley, Herman, 1879- (composer)1
- Paley, Herman, 1879-(composer)1
- Panella, Louis, 1881-19401
- Panella, Louis, 1881-1940 1
- Parr, L. L. (arranger)1