In order to qualify for this list, the character has to be introduced and talked about for a bit in the present tense before it is extremely obvious that they are about to die. Also, the character in question must be named and die in the seven Harry Potter books.

Book one - Harry Collaborates in Killing his Teacher

1. Professor Quirrell

Harry jumped to his feet, caught Quirrell by the arm, and hung on as tight as he could. Quirrell screamed and tried to throw Harry off -- the pain in Harry's head was building -- he couldn't see -- he could only hear Quirrell's terrible shrieks and Voldemort's yells

(...)

"He left Quirrell to die; he shows just as little mercy to his followers as his enemies."

(Harry Potter and the Philosopher's Stone - Chapter 17)

Book two - Harry Continues his Killing Spree

2. Tom Riddle's memory (yeah, this one isn't really a person)

Then, without thinking, without considering, as though he had meant to do it all along, Harry seized the basilisk fang on the floor next to him and plunged it straight into the heart of the book.

There was a long, dreadful, piercing scream. Ink spurted out of the diary in torrents, streaming over Harry’s hands, flooding the floor. Riddle was writhing and twisting, screaming and flailing and then —

He had gone.

(Harry Potter and the Chamber of Secrets - Chapter 17)

Book three - The One Where Everyone Lives!

Book four - Harry isn't the Only One who Kills People

3. Frank Bryce

He was screaming so loudly that he never heard the words the thing in the chair spoke as it raised a wand. There was a flash of green light, a rushing sound, and Frank Bryce crumpled. He was dead before he hit the floor.

(Harry Potter and the Goblet of Fire - Chapter 1)

4. Cedric Diggory (Arguably this is the first "real" death.)

From far away, above his head, he heard a high, cold voice say, “Kill the spare.”

A swishing noise and a second voice, which screeched the words to the night: “Avada Kedavra!”

A blast of green light blazed through Harry’s eyelids, and he heard something heavy fall to the ground beside him; the pain in his scar reached such a pitch that he retched, and then it diminished; terrified of what he was about to see, he opened his stinging eyes.

Cedric was lying spread-eagled on the ground beside him. He was dead.

(Harry Potter and the Goblet of Fire - Chapter 32)

5. Barty Crouch Sr.

I could not hurt Potter; my master needed him. Potter ran to get Dumbledore. I Stunned Krum. I killed my father.”

“Noooo!” wailed Winky. “Master Barty, Master Barty, what is you saying?”

“You killed your father,” Dumbledore said, in the same soft voice. “What did you do with the body?”

“Carried it into the forest. Covered it with the Invisibility Cloak.

I had the map with me. I watched Potter run into the castle. He met Snape. Dumbledore joined them. I watched Potter bringing Dumbledore out of the castle. I walked back out of the forest, doubled around behind them, went to meet them. I told Dumbledore Snape had told me where to come.

“Dumbledore told me to go and look for my father. I went back to my father’s body. Watched the map. When everyone was gone, I Transfigured my father’s body. He became a bone . . . I buried it, while wearing the Invisibility Cloak, in the freshly dug earth in front of Hagrid’s cabin.”

(Harry Potter and the Goblet of Fire - Chapter 35)

6. Barty Crouch Jr. (I'm counting Dementor kisses as death.)

Harry felt a chill in his stomach as Professor McGonagall struggled to find words to describe what had happened. He did not need her to finish her sentence. He knew what the dementor must have done. It had administered its fatal kiss to Barty Crouch. It had sucked his soul out through his mouth. He was worse than dead.

(Harry Potter and the Goblet of Fire - Chapter 36)

Book five - Barely Anyone Important Dies

7. Karkus

“That night a fight broke out, we saw it from the mouth of our cave, lookin’ down on the valley. Went on fer hours, yeh wouldn’ believe the noise. An’ when the sun came up the snow was scarlet an’ his head was lyin’ at the bottom o’ the lake.”

“Whose head?” gasped Hermione.

“Karkus’s,” said Hagrid heavily.

(Harry Potter and the Order of the Phoenix - Chapter 20)

8. Broderick Bode

St. Mungo’s Hospital promised a full inquiry last night after Ministry of Magic worker Broderick Bode, 49, was discovered dead in his bed, strangled by a potted-plant.

(Harry Potter and the Order of the Phoenix - Chapter 25)

9. Sirius Black (The second "real" death.)

Harry saw Sirius duck Bellatrix’s jet of red light: He was laughing at her. “Come on, you can do better than that!” he yelled, his voice echoing around the cavernous room.

The second jet of light hit him squarely on the chest.

The laughter had not quite died from his face, but his eyes widened in shock. Harry released Neville, though he was unaware of doing so. He was jumping down the steps again, pulling out his wand, as Dumbledore turned to the dais too.

It seemed to take Sirius an age to fall. His body curved in a graceful arc as he sank backward through the ragged veil hanging from the arch. . . .

And Harry saw the look of mingled fear and surprise on his godfather’s wasted, once-handsome face as he fell through the ancient doorway and disappeared behind the veil, which fluttered for a moment as though in a high wind and then fell back into place.

(Harry Potter and the Order of the Phoenix - Chapter 35)

Book six - A Bunch of People Die

10. Amelia Bones

“I won’t deny that morale is pretty low at the Ministry,” said Fudge. “What with all that, and then losing Amelia Bones.”

“Losing who?”

“Amelia Bones. Head of the Department of Magical Law Enforcement. We think He-Who-Must-Not-Be-Named may have murdered her in person, because she was a very gifted witch and — and all the evidence was that she put up a real fight.”

(Harry Potter and the Half-Blood Prince - Chapter 1)

11. Emmeline Vance

The Dark Lord is satisfied with the information I have passed him on the Order. It led, as perhaps you have guessed, to the recent capture and murder of Emmeline Vance.

(Harry Potter and the Half-Blood Prince - Chapter 2)

12. Igor Karkaroff

“And they’ve found Igor Karkaroff’s body in a shack up north. The Dark Mark had been set over it — well, frankly, I’m surprised he stayed alive for even a year after deserting the Death Eaters; Sirius’s brother, Regulus, only managed a few days as far as I can remember.” (Harry Potter and the Half-Blood Prince - Chapter 6)

13. Aragog

Dear Harry, Ron, and Hermione,

Aragog died last night. Harry and Ron, you met him, and you know how special he was. Hermione, I know you’d have liked him. It would mean a lot to me if you’d nip down for the burial later this evening. I’m planning on doing it round dusk, that was his favorite time of day. I know you’re not supposed to be out that late, but you can use the cloak. Wouldn’t ask, but I can’t face it alone.

Hagrid

(Harry Potter and the Half-Blood Prince - Chapter 22)

14. Albus Dumbledore (The third "real death".)

Snape gazed for a moment at Dumbledore, and there was revulsion and hatred etched in the harsh lines of his face.

“Severus . . . please . . .”

Snape raised his wand and pointed it directly at Dumbledore.

“Avada Kedavra!”

A jet of green light shot from the end of Snape’s wand and hit Dumbledore squarely in the chest. Harry’s scream of horror never left him; silent and unmoving, he was forced to watch as Dumbledore was blasted into the air. For a split second, he seemed to hang suspended beneath the shining skull, and then he fell slowly backward, like a great rag doll, over the battlements and out of sight.

(Harry Potter and the Half-Blood Prince - Chapter 27)

Book seven - Everyone Dies and Harry Resumes his Killing Spree

15. Hedwig

A second’s relief, and then another burst of green light. The owl screeched and fell to the floor of the cage.

“No—NO!”

The motorbike zoomed forward; Harry glimpsed hooded Death Eaters scattering as Hagrid blasted through their circle.

“Hedwig—Hedwig—”

But the owl lay motionless and pathetic as a toy on the floor of her cage.

(Harry Potter and the Deathly Hallows - Chapter 4)

16. Mad-Eye Moody

Mrs. Weasley ran forward, but the hug Bill bestowed upon her was perfunctory. Looking directly at his father, he said, “Mad-Eye’s dead.”

Nobody spoke, nobody moved. Harry felt as though something inside him was falling, falling through the earth, leaving him forever.

“We saw it,” said Bill; Fleur nodded, tear tracks glittering on her cheeks in the light from the kitchen window. “It happened just after we broke out of the circle: Mad-Eye and Dung were close by use, they were heading north too, Voldemort—he can fly—went straight for them. Dung panicked, I heard him cry out, Mad-Eye tried to stop him, but he Disapparated. Voldemort’s curse hit Mad-Eye full in the face, he fell backward off his broom and—there was nothing we could do, nothing, we had half a dozen of them on our own tail—”

(Harry Potter and the Deathly Hallows - Chapter 5)

17. Rufus Scrimgeour

At that moment, something large and silver came falling through the canopy over the dance floor. Graceful and gleaming, the lynx landed lightly in the middle of the astonished dancers. Heads turned, as those nearest it froze absurdly in mid-dance.

Then the Patronus’s mouth opened wide and it spoke in the loud, deep, slow voice of Kingsley Shacklebolt.

“The Ministry has fallen. Scrimgeour is dead. They are coming.”

(Harry Potter and the Deathly Hallows - Chapter 8)

18. Gregorovitch

“Who was the thief, Gregorovitch?” said the high cold voice.

“I do not know, I never know, a young man—no—please—PLEASE!”

A scream that went on and on and then a burst of green light—

(Harry Potter and the Deathly Hallows - Chapter 14)

19. Ted Tonks

20. Dirk Cresswell

21. Gornuk

“But before we hear from Royal and Romulus,” Lee went on, “let’s take a moment to report those deaths that the Wizarding Wireless Network News and Daily Prophet don’t think important enough to mention. It is with great regret that we inform our listeners of the murders of Ted Tonks and Dirk Cresswell.”

Harry felt a sick, swooping in his belly. He, Ron, and Hermione gazed at one another in horror.

“A goblin by the name of Gornuk was also killed.

(Harry Potter and the Deathly Hallows - Chapter 22)

22. Bathilda Bagshot

“Finally, we regret to inform our listeners that the remains of Bathilda Bagshot have been discovered in Godric’s Hollow. The evidence is that she died several months ago. The Order of the Phoenix informs us that her body showed unmistakable signs of injuries inflicted by Dark Magic.

(Harry Potter and the Deathly Hallows - Chapter 22)

23. Peter Pettigrew

Relashio!” said Ron, pointing the wand at the silver hand, but nothing happened; Pettigrew dropped to his knees, and at the same moment, Hermione gave a dreadful scream from overhead. Wormtail’s eyes rolled upward in his purple face; he gave a last twitch, and was still.

(Harry Potter and the Deathly Hallows - Chapter 23)

24. Gellert Grindelwald

“Kill me, then!” demanded the old man. “You will not win, you cannot win! That wand will never, ever be yours—“

And Voldemort’s fury broke: A burst of green light filled the prison room and the frail old body was lifted from its hard bed and then fell back, lifeless, and Voldemort returned to the window, his wrath barely controllable.

(Harry Potter and the Deathly Hallows - Chapter 23)

25. Dobby

He did not know or care whether they were wizards or Muggles, friends or foes; all he cared about was that a dark stain was spreading across Dobby’s front, and that he had stretched out his own arms to Harry with a look of supplication. Harry caught him and laid him sideways on the cool grass.

“Dobby, no, don’t die, don’t die—”

The elf’s eyes found him, and his lips trembled with the effort to form words.

“Harry . . . Potter . . . ”

And then with a little shudder the elf became quite still, and his eyes were nothing more than great glassy orbs, sprinkled with light from the stars they could not see. (Harry Potter and the Deathly Hallows - Chapter 23)

26. Vincent Crabbe

“C-Crabbe,” choked Malfoy as soon as he could speak. “C-Crabbe . . . ”

“He’s dead,” said Ron harshly.

(Harry Potter and the Deathly Hallows - Chapter 31)

27. Fred Weasley

“No—no—no!” someone was shouting. “No! Fred! No!” And Percy was shaking his brother, and Ron was kneeling beside them, and Fred’s eyes stared without seeing, the ghost of his last laugh still etched upon his face. (Harry Potter and the Deathly Hallows - Chapter 31)

28. Severus Snape

The snake’s cage was rolling through the air, and before Snape could do anything more than yell, it had encased him, head and shoulders, and Voldemort spoke in Parseltongue.

“Kill.”

There was a terrible scream. Harry saw Snape’s face losing the little color it had left; it whitened as his black eyes widened, as the snake’s fangs pierced his neck, as he failed to push the enchanted cage off himself, as his knees gave way and he fell to the floor.

“I regret it,” said Voldemort coldly.

(...)

“Look. . . at. . . me. . . . ” he whispered.

The green eyes found the black, but after a second, something in the depths of the dark pair seemed to vanish, leaving them fixed, blank, and empty. The hand holding Harry thudded to the floor, and Snape moved no more.

(Harry Potter and the Deathly Hallows - Chapter 32)

29. Remus Lupin

30. Nymphadora Tonks

As Ginny and Hermione moved closer to the rest of the family, Harry had a clear view of the bodies lying next to Fred. Remus and Tonks, pale and still and peaceful-looking, apparently asleep beneath the dark, enchanted ceiling. (Harry Potter and the Deathly Hallows - Chapter 33)

31. Colin Creevey

Then Neville nearly walked into him. He was only half of a pair that was carrying a body in from the grounds. Harry glanced down and felt another dull blow to his stomach: Colin Creevey, though underage, must have sneaked back just as Malfoy, Crabbe, and Goyle had done. He was tiny in death.

(Harry Potter and the Deathly Hallows - Chapter 34)

32. Nagini

The slash of the silver blade could not be heard over the roar of the oncoming crowd or the sounds of the clashing giants or of the stampeding centaurs, and yet it seemed to draw every eye. With a single stroke Neville sliced off the great snake’s head, which spun high into the air, gleaming in the light flooding from the entrance hall, and Voldemort’s mouth was open in a scream of fury that nobody could hear, and the snake’s body thudded to the ground at his feet—

(Harry Potter and the Deathly Hallows - Chapter 36)

33. Bellatrix Lestrange

Bellatrix laughed, the same exhilarated laugh her cousin Sirius had given as he toppled backward through the veil, and suddenly Harry knew what was going to happen before it did.

Molly’s curse soared beneath Bellatrix’s outstretched arm and hit her squarely in the chest, directly over her heart.

Bellatrix’s gloating smile froze, her eyes began to bulge: For the tiniest space of time she knew what had happened, and then she toppled, and the watching crowd roared, and Voldemort screamed. (Harry Potter and the Deathly Hallows - Chapter 36)

34. Voldemort