| Pt1 | Katie | Wilkinson | The one reading Suzanne's diary. |
| | Guinevere | | Katie's Persian Cat. |
| | Merlin | | Katie's Labrador. |
| | Suzanne | Bedford | Nicholas' mom. Owner of the diary. Doctor. |
| | Nicholas | Harrison | Suzanne's son. |
| | Matthew | Harrison | Nicholas' dad. Suzanne's husband. Katie's former lover. |
| | Gustavus | | Suzanne's Golder Retriever. |
| | Michael | Bernstein | Doctor. Suzanne's ex-boyfriend. |
| | Isabelle | | Suzanne's grandmother. |
| | Emily | Howe | Suzanne's patient. |
| | Dorris | Lathem | Suzanne's patient. |
| | Earl | Chapman | Suzanne's patient. |
| | Matthew | Wolfe | Suzanne's ex-boyfriend. |
| | Laurie | Raleigh | Katie's friend. |
| | Robin | | Katie's friend. |
| | Susan | Kingsolver | Katie's friend. |
| | Gilda | | Katie's friend. |
| | Lynn | Brown | Katie's friend. |
| | Melanie | Bone | Suzanne's neighbor and friend. |
| | Jack | Brandon | George and Lillian Brandon's son. |
| | George | Brandon | Jack Brandon's dad. Lillian's husband. |
| | Lillian | Brandon | Jack Brandon's mom. George Brandon's wife. |
| Pt2 | Jean | | Matthew's mom. |
| | | Pugatch | Gustavus' veterenarian. |
| Pt3 | Holly | Wilkinson | Katie's mom. |
| | John | Macdowell | Local construction worker. |
| | Meg | Macdowell | John's wife. |
| | Constance | Cotter | Suzanne's doctor. |
| | | Leon | Suzanne's cardiologist. |
| | Monsignor | Dwyer | Priest, Nicholas' baptism. |
| | Dan | Anderson | Pediatrist from Boston. |
| | Dr. Phil | Berman | Suzanne's doctor in Boston. |
| | Dr. Gail | Davis | Suzanne's Cardiologist in Boston. |
| | Michele | Lentini | Suzanne's old bestfriend in Cornwall, New York. |
| Pt4 | Bill | Bone | Melanie Bone's husband. |
| | Phil | Brown | Lynn Brown's husband. |
| | Ashby | Brown | Lynn and Phil's child. |
| | Tory | Brown | Lynn and Phil's child. |
| | Kelsey | Brown | Lynn and Phil's child. |
| | Roscoe | Brown | Lynn and Phil's child. |
| | Bailey Mae | Bone | Melanie Bone's child. |
| | Albert K. | Sassoon | Katie's Gynecologist. |
| Pt5 | Mary | Jordan | Katie's assistant. |
| | Larry | | Owner of the publishing company where Katie works.. |
