| Supporting Character | Show Name | Premiere Date on PBS |
| Alice Nimbletoes | |
| Ms. Mimi | |
| Prunella Deegan | |
| B.J. | |
| Queenie | |
| Bus Driver Bob | |
| Heath the Thesaurus | |
| Zing Zing Zingbah | |
| Paul Hinkle | |
| T-Bone | |
| Hundley | |
| Digit | |
| Annie Tyrannosaurus | |
| Quetzal | |
| Blossom and Chet | |
| Lucy and Grandpa | |
| Aunt Eunice | |
| Herky | |
| Smooch and Winslow | |
| Max and Karla | |
| Tito Chávez | |
| Nelson and Polly | |
| | Supporting Character | Show Name | Premiere Date on PBS |
| Tessie Bear | |
| Bo Baxter | |
| Dongwa Miao | |
| Mr. Noodle | |
| Jessica Ruiz | |
| Neighbor Aber | |
| Gabriela and Gerald | |
| Princess Pea | |
| Noo-Noo | |
| Henry the Green Engine | |
| Dr. Two-Brains | |
| Bear, Ant, and Shark | |
| Animal Junction (setting) | |
| Aristotle and Socrates | |
| Ireon Warthog | |
| Pat Cashman (announcer) | |
| Farmer Pickles | |
| Take-Ou | |
| Flo and Zo | |
| Lisa and Pandro | |
| Socks and Beaverton | |
| Lenni Frazier | |
| | Supporting Character | Show Name | Premiere Date on PBS |
| Padraig and Elly | |
| Kino (main character) | |
| Ttark | |
| Alexandra Picatto (host) | |
| Henri Richard Maurice Dutoit LeFebrve | |
| Keesha Franklin | |
| Elizabeth The Emotional Pig | |
| Ira Flatow (first host) | |
| The Peace Police | |
| LeVar Burton (host) | |
| Badgers, Bats, Foxes | |
| Ringo Starr (regular appearance) | |
| One, Two, Belinda | |
| Emily 'the Vigorous | |
| Nora and Yoko | |
| Furry Boo and Donkey | |
| Sir Vile | |
| Graziella and Bo | |
| Tuck the Turtle | |
| Wanda Gilmore and Joe Talbot | |
| 'Box 3-5-0, Boston, Mass 0-2-1-3-4' (film set) | |
|