| Susannah |
Beck | Conrad and Jeremiah's mother. Aka: Beck. |
| Clay |
Bertolet | Belly's neighbor. |
| Judy |
Blumes | American children's writer. |
| Isabela |
Conklin | Protagonist. Aka: Belly. |
| Ben |
Davis | Taylor's boyfriend. |
| Sandy |
Donatti | Mr. Fisher's real estate agent. |
| Justin |
Ettelbrick | Belly's friend who is having a birthday party. |
| Adam |
Fisher | Conrad and Jeremiah's father. |
| Conrad |
Fisher | Beck's son; Belly's boyfriend. |
| Jeremiah |
Fisher | Conrad's brother. |
| Sophia |
Franklin | Jeremiah's prom partner. |
| Taylor |
Jewel | Belly's best friend. |
| Flora |
Martinez | Jeremiah's prom partner. |
| Junior |
Mint | Belly's stuffed bear. |
| Maureen |
O'Riley | Owner of a fancy hat shop. |
| Rachel |
Spiro | One of Belly's friends. |
| Eric |
Trusky | Conrad's roommate. |
| Cory |
Wheeler | Boy who likes Belly. |
| Alice |
| Belly's best friend in kindergarten. |
| Angie |
| The girl Conrad liked. |
| Ari |
| The R.A. |
| Aubrey |
| Conrad's ex-girlfriend. |
| Boogie |
| Conrad's dog. |
| Cameron |
| Belly's former lover. Aka: Cam. |
| Dan |
| Conrad's friend. |
| Ellen |
| Taylor's family cat. |
| Evelyn |
| One of Belly's friends. |
| Frankie |
| Belly's former busmate. |
| Katie |
| One of Belly's friends. |
| Laurel |
| Belly's mother. |
| Mara |
| Jeremiah's ex-girlfriend. |
| Marcy |
| One of Belly's friends. |
| Mikey |
| Pizza shop cashier; Belly's acquaintance. |
| Nicole |
| The girl Conrad liked last summer. |
| Nona |
| Beck's nurse. |
| Pete |
| Conrad's friend. |
| Sophie |
| The girl in Conrad's dorm. |
| Steven |
| Belly's brother. |
