在 Mission/Organization Index 中，以 O 開頭的條目
在 Person Index 中，以 O 開頭的條目
- O.
- O., A.
- O., E.I.
- O., F.
- O., K.L.
- O., W.L.
- Oakes, W.L.
- Oakeshott, R.E.
- Oberg, O.E.
- Oberholtzer, Elizabeth W.
- Oberholtzer, I.E.
- Oberlin, John Frederic
- Ochiai, J.K.
- OʹConnor, H.B.M. Minister
- Oelka, Alfred
- Oen Tack-chew
- OʹFarrell, John J.
- OʹGara, Cuthbert
- Ogawa
- Ogborn, Kata L.
- Ogden, M.R.
- OgilVie, Charles Lawrence
- Ogren, Peter A.
- Ohlinger, Franklin
- Okuma, Count
- Olcott, Colonel
- Oldfield, Walter H.
- Oldham
- Oldham, H.W.
- Oldham, J.H.
- Oldham, W.F.
- Olesen, P.O.
- Oliver, J.C.
- Olsen
- Olaen
- Olsen, F. Kirkwood
- Olsen, Fawcett
- Olsen, 0.
- Olson
- Olson, A.K. Aeroe
- Olson, Annie
- OlBon, Herman
- Olsson, E.
- Olsson, Josef E.
- Oltmans, A.
- Olyphant, David w.e.
- OʹNeill
- OʹNeill, Frederick William Sco
- Onlay, F.G.
- Oon Teck-chew
- Openshaw, Harry J.
- Orr
- Orr, J.S.
- Orr, H.T. Farmer
- Orr-Ewing, Archibald
- Osborn, George R.
- Osborne, D.E.
- Osgood
- Osgood, Dauphin W.
- Osgood, Elliott I.
- Osias, Cemilo
- Osnes, E.
- Ost, J.B.
- Ostergaard, Niels
- OʹSullivan, Alice
- Ott, R.
- Otte, J.A.
- Outerbridge, L.M.
- Owen
- Owen, Emilie
- Owen, George Sydney
- Owen, J.C.
- Owen, J.W.
- Owen, Mildred May
- Owen, R. Grey
- Owen, Thomas B.
- Oxenham, E.l.
- Oxled