Diana is the name of several characters in the works by Agatha Christie:
- Diana Ashley - (The Idol House of Astarte)
- Diana Brent - (Hallowe'en Party)
- Diana Cleves - (The Second Gong)
- Diana Crale - (Five Little Pigs)
- Diana “Bunch” Harmon - (A Murder is Announced and Sanctuary)
- Diana Horrocks - (A Caribbean Mystery)
- Diana Maberly - (The Cretan Bull)
- Diana Middleton - (The Adventure of the Christmas Pudding)