Dawn French

Deaths in Film

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" is killed (along with Jennifer Saunders) when a swarm of bat-winged dogs lured over by Dakota Fanning collides with them at high speed. (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.