- Grandmother was an ordained minister in the 1930s.
- Lived in Nigeria until the age of 4.
- In the book Bridget Jones's Diary, the main character is obsessed with Firth and his role of Mr. Darcy in the 1995 BBC miniseries Pride and Prejudice. Firth was later cast in the 2001 film adaptation as Mark Darcy.
- His short story, "The Department of Nothing," was included in a 2001 anthology titled Speaking with the Angel.