- 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 and the Search for Buried Treasure
- Oak Island Family
- 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 Bones
- Old Hickory:Andrew Jackson and the American People
- Old Man
- Old Man of the Woods
- Old Man of the Woods
- Olmec Civilization for Kids - History and Mythology America's First Civilization 5th Grade Social ...
- Oma braucht uns - Das Kindersachbuch zum Thema Altwerden, häusliche Pflege und Generationen-Wohnen
- Oma Mines Plattdeutsch Lehrstunde
- Oman
- On Remembrance Day
- On The Farm For Kids
- On the Field with ... Terrell Davis
- 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
- Open Your Mind
- 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
- Ours to Share
- Out of the Ashes
- Outlaw
- Overground Railroad (The Young Adult Adaptation)