Creator
- O.M. Styron and Co.1
- Ohio Bell Telephone Company.1
- Oliver, Paul.1
- Orange News Co.1
- Overly, Charles H.1
- Ovesen, A.1
- Owens Bros-Hillson Co. (Boston, Mass.)1
- P. S. Clark & Company (Darien, Ga.)1
- PCK.1
- Paul C. Koeber Co.1
- Photo & Art Postal Card Co. (New York)1
- Platinachrome Co. (N.Y.)1
- Polhill-Denny Drug Co. (Louisville, Ga.)1
- Post Card Exchange (Birmingham, Ala.)1
- Post Office News & Cigar Store (Hennessy, Okla.)1
- Poving, F. C.1
- Pre Vues (Fla.)1
- Pruss' Photo Postal Studio (St. Louis, Mo.)1
- Putnam Art Co. (Grove Hall, Boston)1
- Rappold, Emil.1