Here's a breakdown:
* Major Characters:
* Cedric Diggory: The most significant death in the book, and a major turning point in the series.
* Frank Bryce: An innocent man killed by Voldemort, but not directly by his hand.
* Barty Crouch Jr. (disguised as Mad-Eye Moody): Technically dies, but not in the way we normally think of death. He is killed by Voldemort for his failure.
* Peter Pettigrew: Though he dies, he doesn't really die in the typical sense. He is killed by his own magic after being disarmed by Harry.
* Minor Characters:
* Many unnamed Death Eaters: They are killed by Voldemort for their failure to capture Harry.
* Several other unnamed characters: The book doesn't explicitly name all the casualties of the Triwizard Tournament, so it's possible there are others.
Overall:
While it's impossible to give an exact number, the most significant deaths are Cedric Diggory and Frank Bryce.
Let me know if you'd like to know more about any of the characters' deaths!