- O'Brien, Dennis (laborer) High near Grand ave
- O'Brien, James (teamster) Stringtown near Levee
- Ocheltree, Wm. A.(printer) Journal of Commerce office
- O'Connor, John (laborer) Perry between Emily and Ross
- O'Connor, Timothy W.(saloon) Levee near Market
- O'Flaherty, Eugene (laborer) Harrison between Cherokee and Shawnee
- Oliver, Thomas B.(clerk) with W. H. Chick & Co.
- Oliver, Walter (carpenter) Boards Grove Hotel
- O'Mear, John (carpenter) Boards Mechanic's Hotel
- O'Shea, Dennis (carpenter) corner of Chouteau ave and Washington
- O'Shaughnessy, Thomas (brickmaker) Boards Ranson's add.
- Otter, Wm. H. Reid, Otter & Bouton Boards John Campbell
- Owens, Henry C. Boards Farmer's Hotel
- Owen, J. R. (medical student) E. side Main between Second and Third