The book of Esther makes no claim whatsoever about who the author is. However, it was clearly written by a Jew who was very familiar with the Persian kingdom, especially the empire customs and law. Also, the author obviously had access to official records of the king of Persia. Suggestions from various commentators regarding the author include Mordecai, Ezra, and Nehemiah. However, it is simply impossible to know who penned the great book of Esther. Although the human author cannot be known, the Divine Author is clearly known. The Holy Spirit of God breathed or inspired the great book of Esther. Through His inspiration, the Holy Spirit has given to the world an inspiring account of the very events God wanted recorded about His sovereign power and faithfulness to deliver His people from their enemies. The dating for the book of Esther is about 465 b.c., toward the end, or after, the reign of King Ahasuerus of Persia. The Lord will help all who humble themselves and call on His name.