- Oamek, Robert - Honey Creek
- O'Connell, William F. - Neola
- O'Donald, Harvey D.- Weston
- Oehlertz, Rudolph - Avoca
- Ohrtman, Henry C. - Avoca
- O'Keefe, John Joseph - Underwood
- Oldehoff, Carl H. - Minden
- Olderog, Hugo Amandus - Treynor
- Oliphant, Leslie Andrew - Wright Twp.
- Oliphant, Lloyd Tracy - Wright Twp.
- Olsen, Adolph Henry - Co. Bluffs
- Olsen, Carl Robert - Wimburn, Pennsylvania
- Olsen, Edmund Thomas - Missouri Valley
- Olsen, Edward E. - Neola
- Olsen, Edward Emil - Neola
- Olsen, George Martin - Neola
- Olsen, Harry A. - Weston
- Olsen, Jens Chris - Avoca
- Olsen, John - Missouri Valley
- Olsen, Joseph A. - Loveland
- Olsen, Leo James - Loveland
- Olsen, Peter - Missouri Valley
- Olsen, Roy John - Missouri Valley
|
|
- Olsen, Walter - Avoca
- Oltman, Harty Rudolph - Co. Bluffs
- O'Neill, Edward - Hancock
- O'Neill, George Francis - Hancock
- O'Neill, James Joseph - Hancock
- Orr, Marian D. - Co. Bluffs
- Orris, Charles Valentine - Hancock
- Osborn, Edward M. - Weston
- Osborn, Frank - Hancock
- Osborn, James Edward - Weston
- Osborne, Warren J. - Oakland
- Osler, Clyde - Carson
- Osler, Harley H. - Griswold
- Osler, Lewis - Carson
- Ostdiek, Henry Lee - Neola
- Ostertog, Fred Oscar - Loveland
- Otis, Charles - St. Louis, Missouri
- Ott, George Henry - Hancock
- Overton, George G. Almon - Walnut
- Ovington, Joseph S. - Co. Bluffs
- Owen, William - Co. Bluffs
- Owens, William Harton - Oakland
|