Northumberland is a county on the north east of England.
Northumberland in the works by Agatha Christie
- Anstell Manor, the home of Richard and Janet Erskine is located in Northumberland. (Sleeping Murder)
- Hugo Lemesurier and his family lives in Northumberland. (The Lemesurier Inheritance)
- Gabriel Stavansson went to three locations in Northumberland, looking for Hermione Leigh Gordon. (The Case of the Missing Lady)