-
oak
-
oak front doors
-
Oakshaft 79
-
Obliteration Charm
-
Obliviate
- Obliviator
-
Oblivious Unction, Dr. Ubbly's
-
Obscurus Books
- "obsolete dingbat"
-
occamy
-
oceans
- Occlumency
- Occlumency (reader's guide)
-
Oculus Reparo
- occupations
- October 31, 1981 [Y1]
-
Oculus Reparo
-
"oddsbodkins"
-
Odo
- Office of House-Elf Relocation
- Office of Misinformation
-
offices
-
Ogden, Bob
-
Ogg
-
Oglethorpe, Dunbar
-
"Oh, Potter, you rotter"
-
Olaf
-
"Old Crowd"
-
old magic (ancient magic)
-
Olde and Forgotten Bewitchments and Charmes
-
Oldman, Gary
-
Oldridge, Chauncey
-
Oliphant, Gondoline
-
Ollerton, Gifford
-
Ollivander, Mr.
-
Ollivander's
-
Omnioculars
-
"on about"
-
One Minute Feasts - It's Magic!
-
One Thousand Magical Herbs and Fungi
-
One-Eyed Witch
- Only One He Ever Feared, The (reader's guide)
-
Oona
-
Opaleye, Antipodean
-
opal necklace
-
opera
-
"Opposition, the"
-
Oppugno
-
Orchideous
- Order of Merlin
-
Order of the British Empire
-
Order of the Phoenix
- Order of the Phoenix, The (reader's guide)
-
Ordinary Wizarding Levels (O.W.L.s)
- organizations
-
orphanage
-
other forms of magic
- Other Minister, The (reader's guide)
-
otter
-
Ottery St. Catchpole
-
Ottery St. Mary
-
Ouagadougou
-
"outhouse"
- Out of the Fire (reader's guide)
-
"over a thousand years ago...Britain at the Founding of Hogwarts
-
Owl Order
-
Owl Post
- Owl Post (reader's guide)
- Owl Post Again (reader's guide)
-
Owl Treats
-
Owlery
- O.W.L.s (reader's guide)
-
O.W.L.s (see Ordinary Wizarding Levels)
-
owls
-
owner of the Railview Hotel
(see Railview Hotel, owner of the)
- Oxford University
-
"Oy!"

