- O'Brien, Lucy
- O'Brien, Sean
- O'Byrne, Nicola
- O'Byrne, Nicola
- O'Connell, Joanne
- O'Connor, Bridget
- O'Connor, Deborah
- O'Connor, Elizabeth
- O'Donnell, Bridget
- O'Dowd, Chris
- O'Hara, Lauren
- O'Hara, Mo
- O'Hara, Natalia
- O'Hare, Gráinne
- O'Kane, Owen
- O'Neill, A.D.
- O'Neill, Amanda
- O'Neill, Martin
- O'Reilly, Bill
- O'Rourke, P. J.
- O'Sullivan, Ronnie
- O'Sullivan, Suzanne
- Oakley, Stu
- Oates, Joyce Carol
- Obasanjo, Olusegun
- Oborne, Martine
- Odo
- Ogilvie, Sara
- Ojari, Daniel
- Olav Lahlum, Hans
- Oldfield, Matt & Tom
- Oliver, Abi
- Oliver, Joshua
- Olivotti, Sergio
- Ollerton, Ollie
- Olley, Darcie
- Olson, Jessica S.
- Olson, Parmy
- Olusoga, David
- Olusoga, Kemi
- Olusoga, Yinka
- Ondaatje, Michael
- Ono, Yoko
- Orczy, Baroness
- Ord, Charlotte
- Orie, Rima
- Orlando, Jade
- Ortega, Julio
- Orwell, George
- Oseid, Kelsey
- Osmond, Richard
- Ostaseski, Frank
- Otis, Andrew
- Ounsley, Jodie
- Owen, Amanda
- Owen, Sid
- Owens, Lisa
- Oxenbury, Helen
- Oxlade, Chris
- Oyemakinde, Tomi
- Oyeyemi, Helen
- Ozawa, Eric
- O’Connor, Katherine Tiernan
- O’Hart, Sinéad
- O’Neill, Eamonn