Dawn French

Film Deaths

The Chronicles of Narnia: Prince Caspian (2008) [Mrs. Beaver]: Dawn does not actually appear in this movie, but it's revealed that her character (she provided the voice of a CGI-animated beaver) had died of old age during the passage of time since the previous movie The Chronicles of Narnia: The Lion, the Witch and the Wardrobe.) (Thanks to Augustin)
Coraline (2009; animated) [Miss Forcible/The Other Miss Forcible]: Playing a dual role in the two realms, "The Other Miss Forcible" ceases to exist after Coraline (Dakota Fanning) frees the trapped spirits. (The real "Miss Forcible" survives the movie.) (Thanks to Tommy)

The Young Ones: Interesting (1982) [Religious Fanatic]: Crushed to death when a giant sandwich crashes through the roof and lands on her. (Played for comic effect.)
French & Saunders: Misery (1993) [Dawn French]: Shot in the stomach with a bazooka by Jennifer Saunders, after several blows to the head with various objects have no effect. (This is a parody of Kathy Bates' death scene from Misery.) (Played for comic effect.)
French & Saunders: French & Saunders Actually (2003) [Dawn French]: Dismembered with a chainsaw (along with Jennifer Saunders) by Felicity Kendal, after Dawn and Jennifer do a parody of Felicity's TV series Rosemary & Thyme. Various body parts are shown flying through the air. (Played for comic effect.)
French & Saunders: Back with a Vengeance (2005) [Various characters]: As "Renée Zellweger", she is shot in the chest by Jennifer Saunders (playing "Nicole Kidman"), due to "Renée's" continuous scene-stealing in a parody of Cold Mountain. (Played for comic effect.)
Psychoville: Series 2, Episode 1 (2011) [Joy]: Killed by Mark Bonnar, who plunges a sharpened pencil into her neck. (Thanks to Brian)

"Experiment IV" (1986) (Kate Bush music video): Killed when the sonic weapon goes out of control. Her body is shown lying in the lab, partially buried under a heap of computer tape.