| Armin Oberbichler (Klagenfurt, AT) | P490 |
| Peter Oberender (Bayreuth) | I146 |
| Ralf Oberheiden (Oberhausen) | P446 |
| Michael Oeff (Brandenburg an der Havel) | K569, P122 |
| Alexandra Öffner (München) | P313 |
| Emanuel Oepangat (Bad Oeynhausen) | P296 |
| Pitt Oetjen (Hannover) | P340 |
| Darlington Okonko (London, GB) | P480, Z74 |
| Hans-Georg Olbrich (Langen) | P505, Z68 |
| Mary Olias (Kiel) | P452 |
| Cecila Oliveri (Mobile, US) | P80 |
| Heyder Omran (Bonn) | P294 |
| Christian Opitz (Berlin) | A193 |
| Grzegorz Opolski (Warsaw, PL) | P511, Z66 |
| Jasmin Ortak (Lübeck) | P377 |
| Jan Ortlepp (Aachen) | P326 |
| Brigitte Osswald (Heidelberg) | P365, P371 |
| Stefan Ostermayer (Frankfurt) | P293, P294, P461 |
| Miodrag Ostojic (Belgrade, CS) | H426, H523 |
| Hano Oswald (Hamburg) | P347 |
| Rainer Ott (Krefeld) | P463, P464 |
| Walburga Otte (Bad Rothenfelde) | P342 |
| Carsten Otto (München) | H520 |
| Tobias Otto (Dresden) | P443, P501 |