Who said: "To be, or not to be, that is the question"?

"To be, or not to be" is the opening phrase of a speech given by Prince Hamlet in the so-called "nunnery scene" of William Shakespeare's play Hamlet, Act 3, Scene 1. In the speech, Hamlet contemplates death and suicide, weighing the pain and unfairness of life against the alternative, which might be worse. The opening line is one of the most widely known and quoted lines in modern English literature, and the speech has been referenced in many works of theatre, literature, and music.

Source: Wikipedia