- Actor Allusion: Young Briony is played by Irish actress Saoirse Ronan. Romola Garai who plays the adult Briony played a Fake Irish in Rory O'Shea Was Here. And she was also involved in a spot of unrequited love involving... drumroll please... James McAvoy. In both films she also plays a girl who spontaneously enters a caregiving job - she also dresses up as a nurse for Halloween in Rory O'Shea Was Here.
- An odd one. Keira Knightley previously died in reality but the witness responsible for her death created a happy ending for her in The Hole.
- Dawson Casting: 25-year-old Romola Garai was cast as 18-year-old Briony.
- Hey, It's That Guy!: Sherlock Holmes (a.k.a. Benedict Cumberbatch) as a chocolate manufacturer and rapist.
- Playing Against Type: A retroactive example for Saoirse Ronan. With films like The Lovely Bones, The Way Back and City of Ember she became known for playing heroic Woobies. This early example shows her playing a Bratty Half-Pint bordering on Yandere.
- Playing with Character Type: Invoked by Keira Knightley. She was approached to play the adult Briony but asked to play Cecilia instead - saying she'd had enough of "coming of age ladies".
- The Red Stapler: The gorgeous green dress worn by Keira Knightley is practically iconic. Replicas of varying quality can still be bought in several online stores.
- Star-Making Role: For Saoirse Ronan. She was cast in The Lovely Bones specifically because Peter Jackson wanted an unknown as Susie. Then this film came out and she got an Oscar nomination.
- Throw It In: In the DVD commentary, Director Joe Wright reveals a lucky fluke that got caught on camera during the scene just before Robbie discovers the school girls massacre. At the point where he removes his helmet, the weather was cloudy. As he looks up the sky, the sun started shining and then got cloudy again the moment he put his head down.