| David Dylan O'Brien-Møller | Ph.d.-studerende | DTU Aqua | |  |
| Barry O'Neill | Professor | DTU Aqua | 35 88 32 59 | |
| Abdou Matinou Ogbon | Gæste ph.d.-studerende | DTU Aqua | | |
| Hans Jakob Olesen | Biolog | DTU Aqua | 21 15 42 53 | |
| Julie Olesen | Biolog | DTU Aqua | 93 51 14 84 | |
| Niels Jørgen Olesen | Emeritus | DTU Aqua | 29 24 43 10 | |
| Mathis Olesen | AC-TAP | DTU Aqua | | |
| Ednaldo Thiesen de Oliveira | Skibsassistent | DTU Aqua | | |
| Jeppe Olsen | Specialkonsulent | DTU Aqua | 93 51 14 53 | |
| Simon Thusgaard Olsen | Gæstestuderende | DTU Aqua | | |