The Book of Esther, also known in Hebrew as "the Scroll" ("the Megillah"), is a book in the third section of the Jewish Tanakh (the Hebrew Bible). It is one of the five Scrolls (Megillot) in the Hebrew Bible and later became part of the Christian Old Testament.

The book relates the story of a Hebrew woman in Persia, born as Hadassah but known as Esther, who becomes queen of Persia and thwarts a genocide of her people. The story forms the core of the Jewish festival of Purim, during which it is read aloud twice: once in the evening and again the following morning. The books of Esther and Song of Songs are the only books in the Hebrew Bible that do not mention God.