| A | B |
|---|
| Charlie Gorden | protagonist and author of the Progress Reports |
| Alice Kinnian | Charlie's teacher at Beekman College and love interest |
| Professor Nemur | scientist in charge of the experiment that heightens Charlie's intelligence |
| Dr. Strauss | neurologist and psychiatrist who performs the operation on Charlie |
| Burt Selden | a friendly graduate student who oversees Charlie's testing |
| Algernon | The white mouse that is the first successful test subject |
| Fay Lillman | Charlie's free-spirited neighbor |
| Rose Gordon | Domineering mother, ashamed of her son's retardation |
| Matt Gordon | Barbershop-supply saleman, father who tried to protect his son from his wife's bullying |
| Uncle Herman | Man who took care of Charlie after Rose expelled him from her home |
| Mr. Donner | The owner of the bakery where Charlie works |
| Frank Reilly and Joe Carp | Employees at Donner's Bakery who often pick on Charlie |
| Gimpy | A employee at Donner's Bakery who is secretly stealing from his boss |
| Fanny Birden | The only bakery employee who is consistently nice to Charlie |
| Dr. Guarino | A quack doctor to whom Charlie is taken as a child |
| Hilda | The nurse who cares for Charlie, thinks changing intelligence is against God's will |
| Minnie | Algernon's companion |
| Mrs. Flynn | Charlie's landlady |
