Penny Parker
The plucky, slightly Sueish heroine. Appeared in all seventeen books.
- Alliterative Name: P.P. for Penny Parker.
- Missing Mom: Her mother died before the series began.
Louise Sidell
Penny's cautious, unathletic best friend. Appeared in sixteen books.
- Catch Your Death of Cold: According to Penny, Louise is more prone to pneumonia than she is.
- Green-Eyed Monster: She can be a bit possessive of Penny and doesn't like to "share" her. From The Cry at Midnight: "Louise considered Penny her dearest friend. Though she would not have admitted it, she was slightly green-eyed whenever another person claimed any of her chum's attention."
- The Klutz: Prone to tripping, bumping into things, etc.
Mrs. Maude Weems
The beloved Parker housekeeper. Appeared in sixteen books.
- Parental Substitute: Penny's mother died before the series began, so kindly Mrs. Weems is the older, reasonable woman in Penny's life.
Jerry Livingston
Crack reporter on The Riverview Star and Penny's love interest. Appeared in fourteen books.
- Put on a Bus: He was gone on military leave for a few books.
- The Bus Came Back: He made a "guest" appearance in Voice From the Cave and returned to the series as a regular in Whispering Walls.
Mr. DeWitt
The Riverview Star's gruff city editor. Appeared in thirteen books.
- Ruptured Appendix: He contracted appendicitis in Ghost Beyond the Gate.
Salt Sommers
The best photographer on The Riverview Star and Penny's friend. Also a part-time airplane spotter. Appeared in eleven books.
- Alliterative Name: Salt Sommers. Both his name and surname start with S.
