| O'Donnell, Mario | (1) |
| O'Donnell, Patricia | (5) |
| Oberndorf, Clarence P. | (1) |
| Obstfeld, Enrique | (3) |
| Ochandorena, Raúl P. | (1) |
| Oelsner, Roberto R. | (4) |
| Ogden, Thomas H. | (3) |
| Ogly de Dupuy, Susana Graciela | (1) |
| Ojman de Kitainik, Hilda | (1) |
| Oldham, John M. | (1) |
| Oliva, María Victoria | (1) |
| Oliveira Velloso, Luiz F. Roehe de | (1) |
| Oliveira, Ismael Walderedo de | (5) |
| Oliviera, Flávio Martinez de | (1) |
| Olshansky, Dmitry | (1) |
| Onaindia, Julián Constantino | (1) |
| Onetto de Carrica, Stella Maris | (5) |
| Onofrio de Serrano, Nora | (1) |
| Ophuijsen, J.H.W. van | (1) |
| Orduz, Fernando | (1) |
| Orduz, Luis Fernando | (1) |
| Oremland, Jerome D. | (1) |
| Orsi, Laura | (2) |
| Ortega, Ricardo Hugo | (2) |
| Ostow, Mortimer | (1) |
| Ostrov, León | (3) |
| Oswald, Luis | (6) |
| Osório, Luiz Carlos | (1) |
| Oxenstein, Sara | (1) |