- O amigo de Darwin
- O Camelo, o Burro e a água
- O capetinha do espaço ou o menino de Mercúrio
- O fantasma escritor e as cartas misteriosas
- O Gato, o Porco e a porcaria
- O Gigante Monstruoso do Lixo
- O Guarda do Rio
- O jardim secreto
- O livro de Gaia
- O maior tesouro da humanidade
- O melhor presente
- O menino d'água e o planeta Netuno
- O menino invisível
- O mistério do pau oco
- O monstro do mar
- O papagaio que faz crá, crá, crá
- O papel de todos
- O passarinho Rafa
- O protesto dos animais
- O pássaro milcores
- O rei do grande rio
- O segredo de Lola
- O veado e a onça
- Ocean Hide and Seek
- Ocean Meets Sky
- Ocean Seasons
- Octavia and Her Purple Ink Cloud
- Odie Needs A New Home!
- Of Flower Which Delight
- Off the Track
- Old Bear and His Cub
- Old Manhattan Has Some Farms
- Old Rock (is not boring)
- Old Turtle
- Oliver's Tree
- Olivia Brophie and Aristotle’s Lantern
- Olivia Brophie and the Pearl of Tagelus
- Olivia Brophie and the Sky Island
- Olivia's Tower
- Olly's Circus
- On a Rainy Day
- On the Move: Mass Migrations
- On the River
- Once Upon a Forest
- Once upon a lime
- Once Upon a Tree
- Once Upon a Virus
- Once Upon a Winter
- Once Upon Another Time
- One Boy's Choice
- One Dark Bird
- One Little Bag: An Amazing Journey
- One Small Hop
- One Wolf Howls
- One Small Hop
- One Wolf Howls
- Onyx
- Oona
- Oonga’s Forest
- Open Wide
- Operazione SalvaPianeta! (Ediz. Alta Leggibilità)
- Origin
- Os guardiões do verde
- Os Jardinautas 3
- Os Jardinautas 4
- Os Jardinautas 5
- Otter Chaos - The Dam Busters
- Otter Chaos!
- Otters' Moon
- Ouch: Tales of Gravity
- Our Great Big Backyard
- Our Little Inventor
- Our Pet Drawings
- Outback All-Stars (Race the Wild #5)
- Outer Space Bedtime Race
- Outside Art
- Over in a River
- Over in the Meadow
- Over in the Wetlands
- Owl & Friends