Outstanding is one of the three passing grades, out of six grades overall, in the Ordinary Wizarding Levels, Nastily Exhausting Wizarding Tests, and Wizards' Ordinary Magic and Basic Aptitude Tests. It is the highest mark possible, immediately above 'Exceeds Expectations'.
Advancing to N.E.W.T.-level
While most professors at Hogwarts set their N.E.W.T. classes entrance standards at 'Exceeds Expectations', meaning that the students must acquire such a grade in their O.W.L. in order to continue, Professor Severus Snape had set his Potion standards to 'Outstanding', meaning only the very best can continue.
Recipients of an O
|Harry Potter||Defence Against the Dark Arts O.W.L.||1996|
|John Dawlish||pre 1990s|