Ordinary Wizarding Level

"Ordinary. Wizarding. Level. Examinations. O.W.L.'s. More commonly known as OWLS. Study hard and you will be rewarded. Fail to do so and the consequences may be... severe."

- Dolores Umbridge to a fifth-year's class

An O.W.L. (Ordinary Wizarding Level) is a subject-specific test taken during Hogwarts students' fifth year, administrated by the Wizarding Examinations Authority. The score made by a student on a particular O.W.L. determines whether or not he or she will be allowed to continue taking that subject in subsequent school years.

Exams
Most O.W.L.s are divided into practical exams and written exams. The O.W.L. is comparable to the Muggle "O level" exam given at the same stage of education (the "O" standing for Ordinary). In 1988, this examination was replaced by the G.C.S.E. in England and the Standard certificate in Scotland, but wizards are under no obligation to change their examinations when Muggles do.

Schedule
O.W.L. exams are administered over a period of two successive weeks at the end of fifth year. Those exams that are divided into two parts will sit the theory portion in the morning and the practical portion in the afternoon, with the exception of the Astronomy practical exam which occurs at night.

First Week

 * Monday - Charms
 * Tuesday - Transfiguration
 * Wednesday - Herbology
 * Thursday - Defence Against the Dark Arts
 * Friday - Study of Ancient Runes

Second Week

 * Monday - Potions
 * Tuesday - Care of Magical Creatures
 * Wednesday - Astronomy, Divination, & Arithmancy
 * Thursday - History of Magic

Unknown

 * Muggle Studies - not specified

O.W.L. Scores
If a student fails an O.W.L. and still wishes to retake it, they are presumably held back in that class. This was the case for Marcus Flint; Professor Severus Snape also remarked in 1996 that Vincent Crabbe and Gregory Goyle need to pass their Defence Against the Dark Arts O.W.L.

Passing Grades

 * O (Outstanding)
 * E (Exceeds Expectations)
 * A (Acceptable)

Failing Grades

 * P (Poor)
 * D (Dreadful)
 * T (Troll)

Confirmed O.W.L.s Received By Subject
All of the O.W.L.'s listed above (expect for Neville's Transfiguration O.W.L., and possibly Harry's and Ron's Astronomy O.W.L.s) qualified for an advancement to N.E.W.T.-level classes.

Behind the scenes

 * In their Defence Against the Dark Arts exam, students are called in order by last name, alphabetically. However, Harry Potter and Hannah Abbott are called at the same time.
 * The only known characters to receive all twelve O.W.L.s are Percy and Bill Weasley, and Barty Crouch Jr. However this is inconsistent with revelations of overlapping class schedules in Harry Potter and the Prisoner of Azkaban. In the third book, it is revealed that Minerva McGonagall had to write several letters to the Ministry in order to obtain a Time-turner for Hermione Granger so that she would be able to attend all her classes when she attempted to take all twelve subjects in her third year. She ultimately dropped two subjects when she was not able to cope with the stress of moving back and forth through time. Percy, Bill, and Crouch Jr would have had to have done something similar to be able to study all twelve subjects and given Hermione's portrayal as a brilliant and overeager student, it seems a bit inconsistent that they would be able to manage, especially in O.W.L year (with the added burden of Prefect duties for Bill and Percy) when she couldn't manage in her third year. However Bill and Percy obtaining twelve O.W.L.s is reveled in Harry Potter and the Chamber of Secrets, before the idea of the clash in class schedules and the need for a Time turner to attend all classes so this may have been an error on the part of J. K. Rowling. Barty Crouch Jr. obtaining twelve O.W.L.s was mentioned by his father during a bout of inane rambling due to the damage to his mind from fighting the Imperius Curse and could have been a delusional mistake on the part of Barty Crouch Sr., although given the Crouch's strong links to the Ministry the idea of Barty Crouch Jr. acquiring a Time Turner is more plausible.