Trivia

The only time Legolas blinks is when he realizes he has been wounded and when Thranduil beheads the orc he is interrogating. This is in keeping with the character, as the only time Legolas blinks in The Lord of the Rings trilogy is when he is strongly surprised.

While the cast was shooting the barrel escape scenes in the specially-constructed indoor "rapids" tank, several of them stated that they had to relieve themselves in the water, since they had to stay in the tank for so long without so much as a lunch break. When Martin Freeman found out he was furious, since Bilbo spends all of his time during that scene directly in the water, and had been swallowing a great deal of it.

During filming, Sir Ian McKellen had to spend several hours in a box, with nothing but a microphone and pictures of the Dwarves for company (the footage would be edited in to make him look taller than the Dwarves), and was so upset by this that he exclaimed "This is not why I became an actor!" The microphone was still on, and everyone on-set heard him as a result. In consolation, the cast and crew surprised him by sticking gifts and encouragement messages into his trailer.

Several of the women who turn out to see Bilbo and the Dwarves leave Lake Town for Erebor are actually tall male crew members, who were dressed up as women to get the proper scale of humans versus dwarves and Bilbo for the shot.

Benedict Cumberbatch suggested writing and reading the Necromancer's Black Speech backwards, and then having the editors reverse the recording to make it sound demonic and unholy.

Alan Lee: The conceptual designer appears as one of the musicians when some of the Dwarves, and Bilbo, leave Laketown. He also appeared as one of the nine Kings of Men in the introductory scenes of The Lord of the Rings: The Fellowship of the Ring (2001).

Royd Tolkien: The great-grandson of J.R.R. Tolkien is in the Extended Edition in a flashback as one of the Captains of the Gondorian Rangers burying the body of the Witch-king of Angmar. This was an homage to Royd's cameo in The Lord of the Rings: The Return of the King (2003) as a Gondorian Ranger at Osgiliath.

Stephen Colbert: As the eyepatch-wearing Lake Town spy who knocks on the door with the walking stick. Colbert, a longtime Tolkien fan and expert, had brought his wife and two of his sons to the shoot. When his scene was completed, Peter Jackson personally presented Colbert with a replica of the sword Sting.

Katherine Jackson: As the barmaid serving Thorin and Gandalf at the Prancing Pony.

Peter Jackson: At the beginning of the movie, as the camera sweeps through the town of Bree, he walks out of the pub looking drunk and eats a carrot. He had a similar cameo in The Lord of the Rings: The Fellowship of the Ring (2001). Jackson also filmed another cameo for this movie. He played another spy in Lake Town, a man who'd hide in a basket and signal his comrades with wild bird calls. The scene was adamantly vetoed by his co-producer and co-writer, Philippa Boyens, and was never used.