O
- O'Barr, J
- O'Brien, Cory
- O'Cinneide, C.S
- O'Connell, Mark
- O'Connor, Joseph
- O'Connor, William
- O'Donnell, Leeanne
- O'Donnell, Peter
- O'Donoghue, Caroline
- O'Hart, Sinéad
- O'Keefe, Megan E
- O'Malley, Bryan Lee
- O'Neal, Kristen
- O'Neill, Kay
- O'Neill, Luke
- O’Sullivan, Colin
- Oakes, J. P.
- Oakes, Stephanie
- Oates, Joyce Carol
- Ochse, Weston
- Ocker, J W
- Oda, Banri
- Oda, Eiichiro
- Oda, Suzuka
- Oda, Tomohito
- Odeldahl, Erik
- Odén, Marija Fischer
- Odenwald, Sten
- Oduor, Okwiri
- Official Dungeons & Dragons licenced
- Offord, Kerryn
- Ogaki, Rokurou
- Ogawa, Chise
- Ogawa, Yoko
- Ogden, Aimee
- Ogewa, Chise
- Oguguo, Odunze
- Oguz, Ömer
- Oh, Axie
- Oh, Temi
- Ohba, Tsugumi
- Ohi, Pikachi
- Ohitsuji, Ei
- Ohkubo, Atsushi
- Ohlsson, Kristina
- Ohsaki, Tomohito
- Ohsawa, Yayoi
- Ohta, Julius
- Ohtaka, Shinobu
- Oima, Yoshitoki
- Oimoto, Jirou
- Ojiro, Makoto
- Okakura, Kakuzo
- Okamoto, Lynn
- Okazaki, Takashi
- Okina, Baba
- Okogwu, Tolá
- Okorafor, Nnedi
- Okosun, Ehigbor
- Okrand, Mark
- Oku, Hiroya
- Okungbowa, Suyi Davis
- Okupe, Roye
- Okura
- Olanders, Jonas Larsson
- Olczak, Martin
- Older, Daniel José
- Older, Malka
- Olin, Elisabeth
- Olivas, Daniel A.
- Oliveira, Anthony
- Oliver, Jamie
- Oliver, Lauren
- Ollerton, Rebecca
- Ollmark, Lena
- Olofsgård, Jonatan
- Olsberg, Karl
- Olson, Jessica S
- Olsson, Johanna
- Olsson, Linn
- Olsson, Sören
- Omata, Yoshie
- Omori, Fujino
- Omu the Rice
- ONE
- Onigunsou
- Onikage, Supana
- Ono, Fuyumi
- Onyebuchi, Tochi
- Oono, Imo
- Oono, Kousuke
- Oosaki, Takahito
- Oowara, Sumito
- Ori, Mita
- Origami, Chiyoko
- Orihi, Chihiro
- Orikawa, Asagi
- ORKA
- Orlando, Steve
- Ormond, Jane
- Orwell, George
- Osada, Hiroshi
- Osawa, Yusuke
- Oseland, Chris-Rachael
- Oseman, Alice
- Oshimi, Shuzo
- Oshiro, Mark
- Osmond, Andrew
- Ostertag, Molly Knox
- Ostow, Micol
- Osunde, Eloghosa
- Oswalt, Patton
- Otomo, Katsuhiro
- Otsmane-Elhaou, Hassan
- Otsuichi
- Otsuji
- Otsuka, Shinichirou
- Ottosson, Ingemar
- Ottsjö, Peter
- Oum, Monty
- Oumiya
- Ovidius
- Ow, Anya
- Owen, Eric
- Owen, Lauren
- Owen, Margaret
- Ox
- Oyebanji, Adam
- Oyeyemi, Helen
- Ozaki, Kaori
- Ozeki, Ruth
- Ozga, Jake