Total Number of Middle School Books: 3,156
Octo-man and the Headless Monster
Odin's Ravens
Of Women and Salt
Old School (Diary of a Wimpy Kid, #10)
Once and for All
Once a Thief
One Boy, No Water
One Crazy Summer
One Day at Horrorland (Goosebumps #16)
One Hundred Shoes
One of Us Is Lying (One of Us Is Lying #1)
One Piece, Vol. 66: The Road Toward the Sun
One Piece, Vol. 67: Cool Fight
One Piece, Vol. 71: Coliseum of Scoundrels
One Piece, Vol. 72
One Piece, Volume 49: Nightime Luffy
One Piece, Volume 50: Arriving Again
One Piece, Volume 51: The Eleven Supernovas