| Oancea | David Ștefan | Baiat | Club Sportiv Navi | 2008 | 854 | 0 | Detalii |
| Oancea | Gabriela | Fata | Scoala Gimnaziala "M.Voiculescu" | 2009 | 410 | 0 | Detalii |
| Oancea | George | Baiat | CSS PLOIEȘTI | 2007 | 1088 | 15953 | Detalii |
| Oancea | Maria | Fata | Renovatio Sport Club | 2007 | 1006 | 0 | Detalii |
| Oancea | Raluca | Fata | Aqua Sport Citius | 2014 | 2891 | 0 | Detalii |
| Oanță | Daria Gabriela | Fata | EnergicLL C.S. | 2010 | 575 | 0 | Detalii |
| Oanță | Rareș Mihai | Baiat | EnergicLL C.S. | 2007 | 557 | 0 | Detalii |
| Obancia | Raul-Antoniu | Baiat | TIMEX București | 2012 | 3188 | 0 | Detalii |
| Obreja | Răzvan | Baiat | Club Sportiv Euro Swimming | 2011 | 1286 | 0 | Detalii |
| Obretin | Maria Alexandra | Fata | ACS Universitar Spiru Haret | 2013 | 3765 | 0 | Detalii |
| Octavian | Lucian | Baiat | Liceul Viitorul Pitești | 2003 | 587 | 15603 | Detalii |
| Ogică | Vlad | Baiat | Dinamo București | 2010 | 2075 | 0 | Detalii |
| Ojog | Maria | Fata | Proper Swimming Education | 2018 | 3614 | 0 | Detalii |
| Olar | Dragoș | Baiat | Dinamo București | 2012 | 2300 | 0 | Detalii |
| Olaru | Andrei Horia | Baiat | Performer C.S. | 2008 | 17 | 0 | Detalii |
| Olaru | Ioan Emanuel | Baiat | Colegiul Emil Racovita | 1994 | 295 | 7910 | Detalii |
| Olaru | Iosif Ciprian | Baiat | Performer C.S. | 1997 | 18 | 0 | Detalii |
| Olaru | Liviu Gabriel | Baiat | CSS PLOIEȘTI | 2015 | 3660 | 0 | Detalii |
| Olaru | Lorena Gabriela | Fata | Cursuri Inot Otopeni | 2015 | 3845 | 0 | Detalii |
| Olaru | Teo | Baiat | Club Sportiv Euro Swimming | 2008 | 2431 | 0 | Detalii |
| Olea | Alexandru | Baiat | CSA Steaua | 2015 | 2644 | 0 | Detalii |
| Olea | Teodora | Fata | CSA Steaua | 2010 | 482 | 0 | Detalii |
| Olenskii | Maxim | Baiat | SSSCJRO Balti | 2008 | 3090 | 0 | Detalii |
| Ologu | Bianca | Fata | Bluemarin Sport Club | 2013 | 2266 | 0 | Detalii |
| Oltean | Alexandra | Fata | Aqua Sport Citius | 2007 | 238 | 0 | Detalii |
| Oltean | Bogdan | Baiat | Dinamo București | 2013 | 1682 | 0 | Detalii |
| Olteanu | Alexandra | Fata | CSM Pitesti | 2012 | 2387 | 0 | Detalii |
| Olteanu | Ana | Fata | CSM Pitesti | 2001 | 645 | 0 | Detalii |
| Olteanu | Ana Maria | Fata | Swimming Team | 2012 | 1422 | 0 | Detalii |
| Olteanu | Andreea | Fata | CS Contratimp | 2004 | 669 | 0 | Detalii |
| Olteanu | Danut Gabriel | Baiat | Independent | 2006 | 3150 | 0 | Detalii |
| Olteanu | David Alexandru | Baiat | Aqua Sport Citius | 2014 | 3246 | 0 | Detalii |
| Olteanu | Ileana | Fata | Atena Sport Club Constanța | 2015 | 2967 | 0 | Detalii |
| Olteanu | Matei | Baiat | Aqua Sport Citius | 2011 | 157 | 0 | Detalii |
| Olteanu | Misha | Fata | ACS Universitar Spiru Haret | 2016 | 2913 | 0 | Detalii |
| Olteanu | Teodor | Baiat | Pescarusul Izvorani | 2014 | 1641 | 0 | Detalii |
| Olteanu | Tudor | Baiat | ACS Amiral | 2014 | 2951 | 0 | Detalii |
| Olteanu | Tudor | Baiat | Proper Swimming Education | 2017 | 3019 | 0 | Detalii |
| Omat | Gabriel | Baiat | Aqua Life Swimming | 2015 | 3812 | 0 | Detalii |
| Oncete | Ema | Fata | Swimming Team | 2013 | 2852 | 0 | Detalii |
| Oniceanu | Radu | Baiat | Delphin Inot Club Constanta | 2018 | 3772 | 0 | Detalii |
| Oprea | Ana Maria | Fata | Aqua Team | 2005 | 878 | 0 | Detalii |
| Oprea | Andreea | Fata | Swimming Team | 2011 | 1557 | 0 | Detalii |
| Oprea | Darius Christian | Baiat | Aqua Life Swimming | 2011 | 68 | 0 | Detalii |
| Oprea | Denis Alexandru | Baiat | Club Sportiv Euro Swimming | 2017 | 3263 | 0 | Detalii |
| Oprea | Emma | Fata | Proper Swimming Education | 2014 | 3020 | 0 | Detalii |
| Oprea | Maria | Fata | ACS Universitar Spiru Haret | 2006 | 921 | 0 | Detalii |
| Oprea | Olivia Gabriela | Fata | Club Sportiv Euro Swimming | 2017 | 3316 | 0 | Detalii |
| Oprea | Patricia | Fata | Bluemarin Sport Club | 2015 | 2577 | 0 | Detalii |
| Oprea | Petru | Baiat | CS Hyperion Brasov | 2009 | 1504 | 0 | Detalii |