| | | Part I |
| Edgar | Sawtelle | Protagonist. |
| Mr. | Schultz | The man from which John bought their land. |
| Mary | Sawtelle | Edgar's grandmother. |
| John | Sawtelle | Edgar's grandfather. |
| Violet | | The Sawtelle's dog. Aka: Vi. |
| Captain | | The massive dog that John likes. Aka: Cappy. |
| Billy | | Captain's owner. |
| Gus | | The puppy that John bought from Billy. Captain's puppy. |
| Gregor | Mendel | A Czechoslovakian monk. |
| Mr. | Adamski | Mr. Schultz's lawyer. |
| Gar | Sawtelle | Edgar's father. |
| Trudy | Sawtelle | Edgar's mother. |
| Page | Papineau | The veterinarian. |
| Almondine | | Edgar's dog. |
| Ida | Paine | The proprietor of Popcorn Corners. |
| Louisa | Wilkes | A woman who visits his nephew and niece. |
| John | Wilkes | Louisa's nephew. |
| Eleanor | Wilkes | John Wilkes's wife. |
| Benny | | Gar's dog. |
| Hector | | The dog that Edgar named. |
| Claude | Sawtelle | Gar's brother. Edgar's uncle. |
| George | Geary | A man who works at the post office. |
| Iris | | One of Edgar's puppies. |
| Alice | | Edgar's old orange Allis-Chalmers C tractor. |
| Alexandra | Honeywell | An actress. |
| Auld | Lang Syne | A singer. |
| Glen | Papineau | Page Papineau's son. A sheriff. |
| Mr. | Brentson | Glen's friend. |
| Forte | | Gar's dog. |
| | | Part II |
| Finch | | Edgar's puppy. |
| Baboo | | Edgar's puppy. |
| Annie | | Glen's assistant. |
| Jim | Frost | Gar's doctor. |
| Tinder | | One of Edgar's dogs. |
| Gordy | Howe | Owner of a truckload. |
| Art | Granger | Gar's friend. |
| Yonder | | Art's dog. |
| Mr. | McCullough | Gar's neighbor. |
| Mrs. | McCullough | Mr. McCullough's wife. |
| Haze | | The third dog that the Sawtelle family owned. |
| Mrs. | Santone | Gar's friend. |
| Deary | | Mrs. Santone's dog. |
| Alvin | Brooks | One of the original breeders at the Fortunate Fields project. |
| Dorothy | Eustice | A dog breeder. Founder of Fortunate Fields. |
| Amos | | Buddy's siblings. |
| Conrad | McCalister | Amos's owner. |
| Buddy | | The most famous dog of Fortunate Fields. |
| Opal | | One of Edgar's dogs. |
| Umbra | | One of Edgar's dogs. |
| Belva | | One of Edgar's dogs. |
| Essay | | One of Edgar's dogs. |
| Pout | | One of Edgar's dogs. |
| Epi | | One of Edgar's dogs. |
| | | Part III |
| Hachiko | | The missing dog. |
| Charles | Aldwin | John's friend. |
| Charles | Aldwin Jr. | Charles's son. |
| Professor | Ueno | Hachiko's master. |
| Ouji | | Charles's dog. |
| Donald | Rogers | Gar's schoolmate. |
| Marjory | Schneider | Gar's schoolmate. |
| Olive | | One of Gar's dogs. |
| Gleam | | A 4-year-old brindle. |
| Alex | Franklin | A boy that Edgar hypnotized. |
| Singer | | A dog that Trudy trained. |
| Indigo | | A dog that Trudy trained. |
| Mr. | Benson | A man who bought one of Sawtelle's dogs. |
| | | Part IV |
| Henry | Lamb | A man that Edgar met. |
| Doctor | Howe | A doctor from Ashland. |
| Adam | | A bartender. |
| Walt | Graves | A man who delivered RFD mail. |
| | | Part V |
| Jasper | Dillon | A truck owner. |