Professor Binns - History of Magic teacher. Professor Binns is the only ghost teacher at Hogwarts. He was very old when he died, sleeping in his armchair. The next day, he got up as a ghost to teach. He is easily the most boring teacher.
Professor Albus Dumbledore - Headmaster of Hogwarts. Dumbledore is hard to miss with his long silver beard and hair, light blue eyes, and half-moon spectacles. Dumbledore is "considered... the greatest wizard of modern times..." He started teacheing at Hogwarts over 50 years ago as the transfiguration teacher. He also worked on alchemy with Nicholas Flamel. Many disagree on his views, such as his picks of teachers. He is also looked down upon for submitting many Muggle-born wizards into Hogwarts.
Argus Filch - Caretaker. Not a teacher, but custodian of Hogwarts. A mean, cold, callous, stingy old man, Filch's sour mood is because of his abilities. Filch is a Squib, a person born of a wizard familt, but can't do any magic. Filch wages a sanitary was against the students and Peeves with the help of his cat, Mrs. Norris.
Professor Flitwick - Head of Ravenclaw House, Charms teacher. A short and energetic man, Professor Flitwick is one of the nicer teachers. Howenver, his size does have some drawbacks. For instance, when Harry's class was practicing Banishing Charms, Neville accidentely sent Flitwick flying across the room!
Rubeus Hagrid - Gamekeeper, Care of Magical Creatures teacher. Hagrid was the person who took Harry from his destroyed house to the Dursleys'. Hagrid is a huge man; his mother being the giantess Fridwulfa. Expelled in his third year, Hagrid stayed at Hogwarts as gamekeeper until Harry's third year where he was promoted to Care of Magical Creatures teacher.
Madam Hooch - Flying Instructor. Madam Hoch teaches flying lessons, and is in charge of the House Quidditch Cup, which she referees. She is extremely knowledgeable about different types of brooms and Quidditch rules.
Professor Minerva McGonagall - Deputy Headmistress, Head of Gryffindor House, Transfiguration teacher. Professor McGonagall is always seen with her square glasses and her black hair in a tight bun. McGonagall is a rather stern woman, one you definately don't want to get on the wrong side of. Saying that, although she's stern, she's also fair and clever. Transfiguration is a extremely dangerous magic, and anyone who can teach it flawlessly has my undying respect. A very powerful witch, she's one of seven Animagi this century, being able to turn herself into a cat.