FO | Arthur | Hastings | Hercule's friend. |
| Hercule | Poirot | Private detective. Arthur's friend. |
1 | | | Revivit - Brings back the natural tone of the hair. Not a dye. |
| Inspector | Japp | Chief Inspector of Scotland Yard. |
2 | Alexander B. | Cust | Ex-military. |
3 | Alice | Ascher | The ABC Murderer's first victim. |
4 | Glen | | Inspector. |
| Dover | | Police constable. |
| | | ABC - Railway guide. |
| Franz | Ascher | Alice's husband. German. Former waiter. |
| Miss | Rose | Alice's former boss where she worked as cook-housekeeper. |
| Mary | Drower | Alice's niece. Parlourmaid. |
| Briggs | | Constable. |
| Dick | Willows | The guy Franz was with the night Alice got killed. |
| Old | Curdie | The guy Franz was with the night Alice got killed. |
| George | | The guy Franz was with the night Alice got killed. |
| Platt | | The guy Franz was with the night Alice got killed. |
5 | Dr. | Kerr | Police surgeon. |
| Tom | | Mary's uncle. Killed in the war. |
| Harry | | Mary's uncle. Went to South America. |
6 | Mrs. | Fowler | Lives across Alice's shop. |
| Edie | | Mrs. Fowler's daughter. |
7 | James | Patridge | The last person known to have seen Alice alive. |
| Albert | Riddell | Platelayer. aka: Bert. |
8 | Carter | | Superintendent of the Sussex police. |
| Crome | | Young inspector in charge of the ABC Murders case. |
| Dr. | Thompson | The famous alienist. |
9 | Elizabeth | Barnard | Second victim. Waitress at Ginger Cat Café. aka: Betty. |
| Mabel | Homer | Muswell Hill schoolgirl. |
| Cappel | | Guilty of Mabel's murder. |
| Kelsey | | Pleasant-faved, intelligent-looking young inspector. |
| Jerome | | Fresh-air, early morning colonel. |
| Mrs. | Merrion | Owned the Ginger Cat Café. |
| Miss | Higley | Waitress at Ginger Cat Café. |
| Mr. | Court | Owned the real estate company Court & Brunskill. |
| Mr. | Brunskill | Owned the real estate company Court & Brunskill. |
10 | | | Llandudno - The name of the Barnards's minute bungalow. |
| Mr. | Barnard | Betty's father. |
| Mrs. | Barnard | Betty's mother. |
| Donald | Fraser | Betty's love interest. Works at Court & Brunskill. |
| Megan | Barnard | Betty's sister. |
13 | Lionel | | Assistant commissioner. |
14 | Carmichael | Clarke | Third victim. Retired throat specialist. aka: Car. |
15 | | | Combeside - Car's house. |
| Deveril | | Car's elderly butler. |
| Mr. | Wells | Police officer. Inspector. |
| Franklin | Clarke | Car's only brother. |
| Charlotte | Clarke | Car's wife who is in bad health. aka: Lady Clarke. |
| Thora | Grey | Car's secretary. |
20 | Capstick | | Lady Clarke's nurse. |
| Logan | | Doctor. |
22 | Mrs. | Marbury | Mr. Cust's landlady. |
| Lily | Marbury | Mrs. Marbury's daughter. |
| Tom | Hartigan | Lily's lover. |
23 | | Anderson | Colonel. |
24 | Mr. | Leadbetter | Went to Regal Cinema to see Not A Sparrow. |
26 | Jameson | | Commissionaire. |
| Geoffrey | Parnell | Was at Regal Cinema at the time of the murder. |
| Sam | Baker | Young fellow. Was at Regal Cinema at the time of the murder. |
27 | George | Earlsfield | Fourth victim. Barber. |
| Roger Emmanuel | Downes | Master Highfield School for Boys. Supposedly fourth victim. |
| | Rice | Inspector. |
| Mr. | Ball | Owned the Black Swan. |
| Mary | Stroud | Works at the Black Swan. |
28 | Jacobs | | Sergeant who filtered the tip claims about ABC Murder case. |
| Bert | Smith | Mrs. Marbury's brother from Canada. |
| Hill | | Young man who talked to Mr. Cust. |
31 | Lucas | | Case personnel. |
| | Strange | Mining engineer. Mr. Cust's Bexhill alibi. |
33 | Mr. | Maynard | Defending solicitor. |