- O Pioneers!
- O planeta confuso
- O príncipe, com prefácio de Paulo Vieira
- O que é o Brasil?
- O Reino das Mulheres
- O sumiço da elefanta
- Oak Island Family
- OCR A Level Law Second Edition
- OCR A-level Sociology Student Guide 1: Socialisation, culture and identity with Family and Youth sub...
- OCR A-level Sociology Student Guide 2: Researching and understanding social inequalities
- OCR A-level Sociology Student Guide 3: Debates in contemporary society: Globalisation and the digita...
- OCR AS/A Level Law Book 1
- OCR GCSE (9-1) Psychology
- OCR GCSE (9–1) Citizenship Studies
- OCR Psychology for A Level Book 1
- OCR Psychology for A Level Book 2
- OCR Sociology for A Level Book 1
- OCR Sociology for A Level Book 2
- Odd One Out
- Odin, Loki, Thor, and More Children's Norse Folktales
- Odliv Na Ostrove Osích Hniezd
- Odpowiednia dziewczyna
- Of Gods, Goddesses, Temples and Priests - Ancient Egypt History Facts Books Children's Ancient Hist...
- Off the Map
- Oh No! Zeus Ate His Wife! Mythology and Folklore Children's Greek & Roman Books
- Old Hickory:Andrew Jackson and the American People
- Old Man
- Old Man of the Woods
- Olmec Civilization for Kids - History and Mythology America's First Civilization 5th Grade Social ...
- Oman
- On Remembrance Day
- On The Farm For Kids
- Once
- Once and for All
- Once Upon A Time
- Once upon a Time Children's European Folktales
- Once Upon a Wombat Time
- One Hen
- One Person, No Vote (YA edition)
- One Room Schools
- One Thousand Paper Cranes
- Opening My Eyes Underwater
- Orations
- Oroonoko
- Our Australian Girl
- Our Australian Girl: Marly walks on the Moon (Book 4)
- Our Australian Girl: Marly's Business (Book 2)
- Our Australian Girl: Meet Marly (Book 1)
- Our Australian Girl: Meet Pearlie (Book 1)
- Our Constitution Rocks
- Our Dogs, Ourselves -- Young Readers Edition
- Our Folktales
- Our Nation's Documents
- Our New Home
- Our Stories, Our Voices
- Our World in Pictures: Countries, Cultures, People & Places
- Ours to Share
- Out of the Ashes
- Outlaw
- Overwhelmed: The Self-care Guide for College Students