The big list of Characters in HP Canon!

Harry's Class Mates
Abbott, Hannah – Hufflepuff
Bones, Susan – Hufflepuff
Boot, Terry – Ravenclaw
Brocklehurst, Mandy – Ravenclaw
Brown, Lavender – Gryffindor
Crabbe, Vincent – Slytherin
Bulstrode, Millicent – Slytherin
Fawcett, ? Miss – Ravenclaw
Finch-Fletchly, Justin – Hufflepuff
Finnigan, Seamus – Gryffindor
Granger, Hermione – Gryffindor
Goyle, Gregory – Slytherin
MacDouglal, Morag – ?
Macmillan, Ernie – Hufflepuff
Malfoy, Draco – Slytherin
Midgen, Eloise – Hufflepuff
Moon, ? – ?
Nott, Theodore – Slytherin
Parkinson, Pansy – Slytherin
Patil, Padama – Ravenclaw
Patil, Parvati – Gryffindor
Perks, Sally-Anne – ?
Potter, Harry – Gryffindor
Thomas, Dean – Gryffindor
Turpin, Lisa – Ravenclaw
Weasley, Ronald – Gryffindor
Zabini, Blaise – Slytherin

Other Years
Ackerly, Stewart. Ravenclaw. -3
Bell, Katie – Gryffindor Chaser. +1
Baddock, Malcolm – Slytherin. -3
Branstone, Eleanor – Hufflepuff. -3
Cauldwell, Owen – Hufflepuff. -3
Chang, Cho – Ravenclaw Seeker +1
Clearwater, Penelope – Ravenclaw. +3
Creevey, Colin – Gryffindor. -1
Creevey, Dennis – Gryffindor. -3
Diggory, Cedric – Hufflepuff Seeker [later Triwizard Champion] +2
Dobbs, Emma. -3
Flint, Marcus – Slytherin Quidditch Captain. +4(?)
Higgs, Terence – Slytherin Seeker
Johnson, Angelina – Gryffindor Chaser. +2
Jordan, Lee – Gryffindor. +2
Madley, Laura – Hufflepuff. -3
McDonald, Natalie – Gryffindor. -3
Pucey, Adrian – Slytherin Chaser
Pritchard, Graham – Slytherin. -3
Quirke, Orla – Ravenclaw. -3
Spinnet, Alicia – Gryffindor Chaser. +2
Summers, Mr ?
Warrington, Mr – Slytherin. +3
Weasley, Fred – Gryffindor Beater. +2
Weasley, George – Gryffindor Beater. +2
Weasley, Percey – Gryffindor Prefect [later Head Boy]. +4
Whitby, Kevin – Hufflepuff. -3
Wood, Oliver – Gryffindor Keeper and Quidditch Captain. +4




Teachers
Professor Binns – History of Magic
Professor Dippet – Headmaster in Riddle's day
Professor Dumbledore, Albus – Headmaster. Originally Transfiguration
Professor Flitwick – Charms. Ravenclaw HoH
Hagrid, Rubeus – Gamekeeper, later Care of Magical Creatures teacher
Madam Hooch – Quidditch
Lockhart, Gilderoy – Defence Against the Dark Arts [Chamber of Secrets]
Professor Lupin, Remus J – Defence Against the Dark Arts [Prizoner of Azkaban]
Professor McGonagall, Minerva – Transfiguration. Gryffindor HoH. Deputy Head
Moody, Alastor (Mad-Eye) – DADA [GoF] ex-Auror
Madam Pince – Librarian
Madam Pomfrey, Poppy – Nurse
Professor Sinistra – Astronomy
Professor Snape, Severus – Potions [later DADA]. Slytherin HoH [later HM]
Professor Sprout – Herbology. Hufflepuff HoH
Professor Trelawney, Sybill – Divination
Professor Quirrell – Defence Against the Dark Arts [Philosopher's Stone]
Professor Vector – Arithmancy

Ghosts
Bloody Baron, the
Professor Binns – History of Magic professor
Fat Friar, the
Moaning Myrtle
Nearly Headless Nick, Sir Nicholas de Mimsy
Peeves (poltergiest)

Random People
Bagman, Ludo – Dept of Magical Games and Sports, ex-beater for Wimbourne Wasps [GoF]
Bryce, Frank [Muggle gardener  murdered by Voldemort in GoF]
Bode – Unspeakable (Department of Mysteries) [GoF]
Croaker – Unspeakable (Department of Mysteries) [GoF]
Crockford, Doris
Delacour, Fleur [Beaubatons student, Triwizard Champion. Later married to Bill Weasley]
Diggle, Dedalus
Dursley, Dudley [Muggle]
Dursley, Petunia [Muggle]
Dursley, Vernon [Muggle]
Fletcher, Mundungus [common criminal sort – later in Order of the Phoenix]
Fudge, Cornelius [Minister for Magic]
Gregorovitch [wandmaker]
Griphook [Goblin at Gringotts]
Jorkins, Bertha [Ministry employee murdered by Voldemort in GoF]
Karkaroff, Igor [Durmstrang Headmaster]
Krum, Victor [Durmstrang student, Triwizard Champion]
Madame Maxime, Olympe [Beauxbatons Headmistress]
Mockridge, Cuthbert – Head of Goblin Liason [GoF]
Peasgood, Arnold – Obliviator for Accidental Magic Reversal [GoF]
Poliakoff [Durmstrang student]
Polkiss, Piers [Muggle, Dudley's Friend]
Prang, Ernie [Driver of Knight Bus]
Madam Rosmerta [landlady of the Three Broomsticks]
Shunpike, Stan [Conductor on Knight Bus]
Skeeter, Rita [Journalist for the Daily Prophet]
Wimple, Gilbert – Committee on Experimental Charms [Gof]

Famous Witches and Wizards
Agrippa [wizard, Chocolate Frog card]
Cadogan, Sir [portrait]
Circe [witch, CFc]
Cliodna [druidess, CFc]
Emeric the Evil
Flamel, Nicholas
Gregory the Smarmy
Grindelwald
Grunnion, Alberic [wizard, CFc]
Gryffindor, Godric
Hengist of Woodcroft [wizard, CFc]
Hufflepuff, Helga
Merlin [wizard, CFc]
Morgana [witch, CFc]
Paracelus [wizard, CFc]
Ptolemy (wizard, CFc]
Ravenclaw, Rowena
Slytherin, Salazar
Uric the Oddball
Voldemort – You-Know-Who, the Dark Lord, Tom Marvolo Riddle
Wendelin the Weird

Named Death Eaters
Avery
Crabbe Snr
Barty Crouch Jnr
Dolohov, Antonin
Goyle Snr
Karkaroff, Igor
Lestrange, Bellatrix/Rodolphus/Rastaban 
Macnair
Malfoy, Lucius
Mulciber
Nott Snr
Pettigrew, Peter – also Wormtail, Scabbers
Rookwood, Augustus (spy in Dept of Mysteries)
Rosier
Travers 

Other canon spellings