O
- Dr Miriam O'Connor
- Dr Kelly O'Donovan
- Dr Joy O'Hazy
- Bithia O’Brien
- Margaret O’Brien-Tomko
- Prof Mike O’Connor AM
- Dr Timothy O’Dowd
- Dr Catherine O’Hare
- Dr Edward O’Mahony
- Jessie O’Mahony
- Dr Erin O’Reilly
- David O’Rourke OAM
- Dr Robert O’Shea
- Justin M O’Sullivan
- Dr Susannah O’Sullivan
- Prof Andreas Obermair
- Dr Helena M Obermair
- Dr Megan Ogilvie
- Dr Karaponi Okesene-Gafa
- Dr Jeannie Oliphant
- Dr Olufela Olutayo Ifaturoti
- Dr John Ombiga
- Dr Benjamin A Onyeka
- Dr Cindy Ooi
- Hannah Orr
- Sarah Ortenzio
- Dr Kym Osborn
- Dr Geoff Otton
- Dr Megan Overdevest
- Wemi Oyekanmi
- Dr Charlotte Oyston