| 1 | Don | Tillman | Narrator. Associate Professor. Works at the Genetics Department.
Aka: Donald. |
| | Gene | Barrow | Don's friend. Head of the Psychology Department. |
| | Claudia | Barrow | Gene's wife. Clinical Psychologist. |
| | Eva | | House cleaner. |
| | Elizabeth | | Claudia's friend. Computer Scientist. |
| | Julie | | Asperger Syndrome Counselor. |
| 2 | Daphne | Speldewind | Don's friend and neighbor. Afflicted with Alzheimer's disease. |
| | Charlotte | Lawrence | Dean at the school where Don and Gene works. a.k.a. Dean. |
| 3 | Helena | | Personal assistant of Gene. |
| | Eugenie | Barrow | Daughter of Gene and Claudia. |
| | Carl | Barrow | Half-brother of Eugenie. Gene's son. |
| | Laszlo | Hevesi | Works in the Physics Department. |
| | Kevin | Yu | Honor student of Don. Caught cheating. |
| 4 | Craig | | One of the men who attended the Table for Eight, a matchmaking organization. |
|
| | Danny | | Also attended the Table for Eight. |
| | Olivia | | Anthropologist. |
| | Gerry | | Lawyer. |
| | Sharon | | Accountant. |
| | Maria | | Nurse. |
| 5 | Fabienne | | Attended the singles party. |
|
| | Frances | | Participated at a speed dating activity. |
| 6 | Rosie | Jarman | PhD Candidate in Psychology. Works part-time at the Marquees of Queensbury bar. |
| | Jason | | One of the security personnel at Le Gavroche. |
| 7 | Esther | | Colleague of Don. |
|
| | Bethany | | Dated Don. Vegetarian. |
| 8 | Phil | Jarman | Rosie's father. |
| 10 | Eamonn | Hughes | Cardiologist. Went to the same medical school as Rosie's mother. |
| | Belinda | Hughes | Eamonn's wife. Nurse. |
| 11 | Peter | Enticott | Doctor. On the medical faculty at Deakin University. |
| | Alan | McPhee | Oncologist. Went to the same medical school as Rosie's mother. Deceased. |
| | Natalie | | Alan's daughter. |
| | Regina | | Personal Assistant of Dean Lawrence. |
| 14 | | Collie | Doctor. Same graduating class of Rosie's mother. |
| | Brian | Joyce | Doctor. Same graduating class of Rosie's mother. |
| | | Walsh | Doctor. Same graduating class of Rosie's mother. |
| | Jenny | Broadhurst | Wife of Roderick |
| | Roderick | Broadhurst | a.k.a. Rod. Doctor. Same graduating class of Rosie's mother. |
| 15 | Ralph | Browning | Doctor. Same graduating class of Rosie's mother. |
| | Miranda | Ball | Doctor. Same graduating class of Rosie's mother. |
| | Gerry | Lucas | Doctor. Same graduating class of Rosie's mother. |
| | Martin | van Krieger | Doctor. Same graduating class of Rosie's mother. |
| | Anwar | Khan | Doctor. Same graduating class of Rosie's mother. |
| | Amghad | | Golf Club boss. |
| 16 | Bianca | Rivera | Met all the criteria of The Wife Project. |
| 17 | Stefan | | PhD Candidate in Psychology. Rosie's date. |
| | Klara | | Hungarian post doctorate from Physics Department. |
| | Michelle | | Don's sister. Deceased. |
| 19 | | Lefebvre | Professor at Medical Research Institute. |
| | Gerhard | von Deyn | Doctor. Same graduating class of Rosie's mother. Deceased. |
| | Brigitte | von Deyn | Daughter of Gerhard. |
| | Geoffrey | Case | Doctor. Same graduating class of Rosie's mother. Deceased. |
| | Isaac | Esler | Psychiatrist |
| | Solomon M. | Freyberg | Cosmetic Surgeon. |
| 20 | Margaret | Case | Geoffrey's mother. |
| 21 | Gary | Parkinson | Went to the same High School as Don. |
| 23 | Judy | Esler | Wife of Isaac. |
| 25 | Frank | | Works as tour guide at World Trade Center Site. |
| | Mary | Keneally | Associate Professor of Psychiatry at Columbia University. |
| | Dave | | Baseball fan. |
| | David | Borenstein | Dean of Medicine at Columbia University. |
| 28 | Bernadette | O'Connor | Rosie's mother. |
| 33 | Nick | | Head waiter at Le Gavroche. |
| 34 | Trevor | Tillman | Don's brother. |
