Big Finish
Cast and Crew List: O
- Maureen O'Brien (cast in 37 episodes, e.g. Vicki in The Secret History)
- Shane O'Byrne (crew in 8 episodes, e.g. Sound Design by in Torchwood Soho: Ascension)
- Mikey O'Connor (cast in 2 episodes, e.g. Thomas Eckert in Assassin in the Limelight)
- Patrick O'Connor (crew as Written by in Odyssey)
- Emerald O'Hanrahan (cast in 2 episodes, e.g. Clementine Scrivener in Philip Hinchcliffe Presents: The Ghosts of Gralstead)
- Charlotte O'Leary (cast in 4 episodes, e.g. Poppy in Aliens Among Us - Part 2: Love Rat)
- Kevin O'Leary (cast as William Burke in Medicinal Purposes)
- Daniel O'Mahony (crew in 4 episodes, e.g. Writer in Return to the Web Planet)
- David O'Mahony (cast in 5 episodes, e.g. Aleksander in Torchwood Soho: Ascension)
- Daniel O'Meara (cast in 4 episodes, e.g. Ketch in Terror of the Sontarans)
- Siri O'Neal (cast in 6 episodes, e.g. Colonel Emily Chaudhry in The Coup)
- Maggie O'Neill (cast in 2 episodes, e.g. Lysandra Aristedes in Black and White)
- Gerry O'Toole (cast in 2 episodes, e.g. Lowell in Blood of the Daleks)
- Maureen Oakeley (cast as Dr. Dale Pargeter in Minuet in Hell)
- Lawrence Oakley (crew in 8 episodes, e.g. Sound in Frostfire)
- Maureen Oakley (cast as Pilot Susan Roberts in Red Dawn)
- Jolade Obasola (cast as Jasmine Jenning in End Game)
- Tracy-Ann Oberman (cast in 38 episodes, e.g. Temperance Finch in Deimos)
- Bill Oddie (cast as Red Jasper in Doctor Who and the Pirates)
- Amaka Okafor (cast in 4 episodes, e.g. Agnes / Legend-F in Ravenous 3: Deeptime Frontier)
- Nneka Okoye (cast in 3 episodes, e.g. Athelia in Most Wanted: Fast Times)
- Dolly Oladini (cast in 4 episodes, e.g. Mother/Till Girl in Iris Wildthyme Series 3: The Iris Wildthyme Appreciation Society)
- Eddie de Oliveira (cast as Willis in Davros)
- Ingrid Oliver (cast in 45 episodes, e.g. Helen/Oracle in Project: Destiny)
- Mark B. Oliver (crew as Writer in Wildthyme Reloaded: Murder at the Abbey)
- Mark B Oliver (crew as Writer in Dark Convoy)
- Mark Oliver (cast in 2 episodes, e.g. Kolspen of Unvoss in Gallifrey VI: Renaissance)
- Sean Oliver (cast as Chief Blue in Red)
- Travis Oliver (cast in 6 episodes, e.g. Chris Cwej in Damaged Goods)
- Philip Olivier (cast in 30 episodes, e.g. Hex in Signs and Wonders)
- Maggie Ollerenshaw (cast in 7 episodes, e.g. Audrey McShane in Love and War)
- Katarina Olsso (cast in 2 episodes, e.g. Headhunter in Blood of the Daleks)
- Katarina Olsson (cast in 29 episodes, e.g. Shan/Computer/Earpiece Voice in Davros)
- Wanda Opalinska (cast in 5 episodes, e.g. Nadia Vasney in The Night Witches)
- Vivian Oparah (cast in 6 episodes, e.g. Tanya Adeola in Class - Volume One: Gifted)
- Stuart Organ (cast as Helgert Teveler in The Seeds of War)
- Kate Orman (crew in 2 episodes, e.g. Writer in Short Trips Volume 03: The Five Dimensional Man)
- Sunny Ormonde (cast in 4 episodes, e.g. Molly in Circular Time: Summer)
- Tamzin Outhwaite (cast in 2 episodes, e.g. Morton in Forty 1: God of War)
- Sarah Ovens (cast as Kate in The Conspiracy)
- Sarah Ovens (cast as The Cell in The Highest Science)
- Chris Overton (cast as Terrill/Levek in The Brood of Erys)
- Indra Ové (cast in 3 episodes, e.g. Tayna Vandermoy in The Robots Volume Two: Robots of War)
- Glyn Owen (cast as Commander Harlon in Nekromanteia)
- Jonathan Owen (cast in 3 episodes, e.g. Antranak in The Eye of the Scorpion)
- Kai Owen (cast in 25 episodes, e.g. Rhys Williams in Forgotten Lives)
- Merryn Owen (cast as Revnon in Time Works)
- Sion Tudor Owen (cast as Mr Collins in Poppet)
- Jude Owusu (cast in 4 episodes, e.g. Dransino in The Time War - Series 3: State of Bliss)
- Mateo Oxley (cast as Emperor Merdiven in Empire of Shadows)
- Emerald O’Hanrahan (cast as Mira in The Children of Seth)
- Charlotte O’Leary (cast in 5 episodes, e.g. Waitress in Corpse Day)
- Maggie O’Neill (cast in 2 episodes, e.g. Captain Lysandra Aristedes in Project: Destiny)