- Oobi - The main character of the show, a curious hand puppet with hazel eyes.
- Uma - Oobi's overdramatic three-year-old sister who wears a barrette.
- Kako - Oobi's excitable and slightly arrogant best friend who often wears a red cap. His eyes are green.
- Grampu - Oobi and Uma's caring but very unlucky grandfather. He has hazel eyes.
- Inka - Oobi and Angus' piano teacher. Grampu has a crush on her.
- Angus - A friend of Oobi, Uma and Kako who is almost always nervous.
- Mrs. Johnson - Oobi's elderly neighbor and one of Grampu's friends.
- Mamu and Papu - Kako's good-natured parents, who encourage others to try new things.
- Maestru - Oobi and Kako's singing instructor.
- Frieda - A foot puppet and a good friend of Oobi.
- Moppie - Uma's best friend from preschool.
- Bella - The owner of the local grocery store.
52 long-form episodes and at least 48 shorts of Oobi were aired over three seasons.