- Actor Allusion: One of the survivors is played by Karen Meagher. You know her best as Ruth Beckett.
- Fake American: Australian Rose Byrne and, somewhat oddly, Briton Idris Elba as American soldiers.
- Most of the other U.S. soldiers seem to be Britons playing them.
- Hey, It's That Place!: Don and Alice are hiding out in the same farm from Children of Men.
- Throw It In!: The film was supposed to end with the shot of the parked helicopter. The director and two producers flew out to Paris at the last minute to add the extra bit on.
- What Could Have Been:
- Early script ideas included following what happened next to Jim, Hannah and Selena, or a concurrent story during the 28 days where a SAS team was sent into London to retrieve the Prime Minister or the Queen. Danny Boyle had intended to direct but was busy filming Sunshine.
- The script had Scarlet dying before Doyle. However, the director felt that there was more potential for fear and tension if Doyle died first - and swapped the deaths around.
Trivia / 28 Weeks Later