|The following is a list of main and recurring characters in the The Backyardigans series.
- Uniqua is an adventurous creature known as a "Uniqua," and the only character to appear in every episode. Her speaking voice is provided by LaShawn Tináh Jefferies.
- Pablo is a frenetic penguin, who is often afraid to try new things. His speaking voice is provided by Zach Tyler Eisen (season 1) and Jake Goldberg (seasons 2-4).
- Tyrone is an easygoing, affable moose. His speaking voice is provided by Reginald Davis (seasons 1-2), Jordan Coleman (seasons 2-3) and Chris Grant (season 4).
- Tasha is a somewhat bossy hippo. Her speaking voice is provided by Naelee Rae (seasons 1-2) and Gianna Bruzzese (seasons 3-4).
- Austin is the "new kangaroo on the block." He is quick-witted and somewhat shy. His speaking voice is provided by Jonah Bobo.
- Sherman is a small and occasionally shy Worman. He is voiced by Reginald Davis in season one and Oliver Wyman in season four.
- Dragon is, as his name implies, a green dragon owned by King Pablo. He is voiced by Oliver Wyman.
- Wormans are various worm-like creatures living in the backyard. They are voiced by Oliver Wyman.
- Robot Roscoe is a well-behaved robot owned by Austin. He appears only in the fourth season.
- The giant robot is an unnamed robot made of silver. He appears in the third and fourth seasons.
- The Can't-See-Ums are small insects that are extremely difficult to see.
- The giant clam is a large, sea-dwelling mollusk who pants and acts like a dog.
- The announcer is an unseen narrator whose voice is heard in four episodes of the series.