Author of the Book of 2 Samuel

Author - Samuel (According to Tradition). The original ancient Hebrew manuscripts recorded the books of Samuel as only one book. The first time these books were divided was in the Septuagint, the Greek version of the Hebrew Scriptures, and they were referred to as the First and Second Books of Kingdoms. 1 and 2 Kings were referred to as the Third and Fourth Books of Kingdoms. When looking closely at the King James version of the Bible the titles are still arranged in this way.

Link: https://bible-history.com/old-testament/bookofsamuel