Cedric Diggory is a Hufflepuff who is a year above Harry at Hogwarts School of Witchcraft and Wizardry. Cedric is the Captain of the Hufflepuff Quidditch team and plays Seeker. During his fifth year, Cedric is chosen as a Hogwarts school champion and competes in the Triwizard Tournament. During the last task Cedric and Harry touch the Triwizard cup at the same time, intending to have a shared win for Hogwarts. Unfortunately the cup is a Portkey and both Harry and Cedric are transported to a graveyard. Cedric is then killed by Peter Pettigrew.
Cedric is made captain of the Hufflepuff Quidditch team and plays Seeker. Oliver Wood describes Cedric as an excellent Seeker and warns his team that Cedric has put a very strong side together. Cedric is also described as "good-looking" and "strong and silent", by the female Gryffindor team members. During the match dementors swarm around the field and Harry faints and falls off his broomstick. Cedric caught the Snitch just after Harry Potter fell. When Cedric realized what had happened, he tried to call it off and asked for a rematch. But it was decided that Hufflepuff won fair and square. 
Cedric attends the Quidditch world cup with his father Amos Diggory. Cedric and his father take the same portkey as the Weasleys and Harry and Hermione. Cedric's father brags about Cedric's quidditch abilities and Cedric is embarrassed.  Cedric is chosen as the Hogwarts school champion and competes in the triwizard tournament. Before the first task, Harry warns Cedric that they will be facing dragons. Cedric was the first champion to compete and faced the Swedish Short-Snout dragon. Cedric Transfigured a rock into a Labrador to try and distract the dragon. But he got burned while getting his egg.  Cedric takes Cho Chang to Yule Ball. Since Harry warned Cedric about the dragons, Cedric thinks it is only fair to give Harry a hint to "take a bath, and - er - take the egg with you, and - er - just mull things over in the hot water". Harry is angry that Cedric is dating Cho and doesn't want to take his advice. Later it is reveled that fake Mad-Eye-Moody (aka Barty Crouch Jr.) helped Cedric figure out what to do to get the clue from the egg. In the final task Cedric is attacked by Viktor Krum who was placed under the imperius curse. Both Cedric and Harry make it to the center of the maize and decide to grad the cup at the same moment. The cup turns out to be a Portkey and both Harry and Cedric are taken to a graveyard. Cedric is quickly killed by Peter Pettigrew who uses the killing curse after Lord Voldemort instructs him to "kill the spare".  Cedric's "ghost" is among those that come out of Lord Voldemort's wand. He encourages Harry to keep fighting Lord Voldemort and asks that Harry take his body back to his parents. 
Cedric is honored by Dumbledore at the end of the year banquet, asking all the students to raise their glasses to Cedric Diggory.
"Cedric was a person who exemplified many of the qualities that distinguish Hufflepuff house. He was a good and loyal friend, a hard worker, he valued fair play. His death has affected you all, whether you knew him well or not. I think that you have the right, therefore, to known exactly how it came about. Cedric Diggory was murdered by Lord Voldemort. The Ministry of Magic, does not wish me to tell you this. It is possible that some of your parents will be horrified that I have done so - either because they will not believe that Lord Voldemort has returned, or because they think I should not tell you so, young as you are. It is my belief however, that the truth is generally preferable to lies, and that any attempt to pretend that Cedric died as the result of an accident, or some sort of blunder of his own, is an insult to his memory. [...] Remember Cedric. Remember, if the time should come when you have to make a choice between what is right and what is easy, remember what happened to a boy who was good, and kind, and brave, because he strayed across the path of Lord Voldemort. Remember Cedric Diggory" 
Harry Potter continues to have nightmares about Cedric's death. He also gets furious at Dolores Umbridge when she tries to suggest that Cedric's death was not caused by the return of Lord Voldemort. Harry eventually gives an interview to Rita Skeeter that is published in the Quibbler about the return of Lord Voldemort, how Cedric was really killed, and everything that happened in the graveyard. Cho Chang is also still dealing with the death of Cedric. She is known to cry in bathrooms. She longs to talk about Cedric with Harry, but Harry does not want to talk about him with her.
Portrayals within films
Cedric is very handsome and is described as a "pretty boy".
"Exceptionally handsome, with his straight nose, dark hair, and grey eyes" 
Cedric is a true Hufflepuff. He is hardworking and values fair play.
Magical accomplishments and skills
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Cedric is the son of Amos Diggory. His mother is only called Mrs. Diggory, so we do not know her first name.
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In popular culture
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