Amos names himself
The opening line presents the book as the words of Amos. It places his ministry during the reign of Uzziah in Judah and Jeroboam II in Israel, shortly before a major earthquake (Amos 1:1). So the straightforward biblical answer is that Amos was the author whose prophetic words form this book.
Amos spoke mainly to the northern kingdom of Israel, though he came from Tekoa, a town in Judah south of Jerusalem. His message confronted a wealthy society that worshipped outwardly while exploiting poor and vulnerable people. He called Israel back to justice, humility, and wholehearted faithfulness to God (Amos 2:6-7; Amos 5:21-24).
The words of Amos, who was among the herdmen of Tekoa, which he saw concerning Israel in the days of Uzziah king of Judah, and in the days of Jeroboam the son of Joash king of Israel, two years before the earthquake.
A shepherd called by God
Amos was not presented as a professional prophet or as part of a prophetic family. When Amaziah, a priest at Bethel, told him to leave Israel, Amos explained that he had worked as a herdman and tended sycomore fruit. Then he said the Lord took him from that work and told him to prophesy to Israel (Amos 7:12-15).
That detail matters. Amos did not claim authority because of status, education, or connections. His authority came from God's call. The book repeatedly shows a God who sees what leaders and worshippers may prefer to ignore, especially dishonesty, violence, and the mistreatment of the needy (Amos 4:1; Amos 8:4-6).
Then answered Amos, and said to Amaziah, I was no prophet, neither was I a prophet's son; but I was an herdman, and a gatherer of sycomore fruit: And the Lord took me as I followed the flock, and the Lord said unto me, Go, prophesy unto my people Israel.
What about the book's final form?
The book itself connects its messages with Amos, and Christians have traditionally received it as his prophecy. Like other biblical books, its speeches and visions were preserved in written form for God's people. The text does not tell us every detail about when each message was recorded or whether others helped preserve it.
Still, the central point is clear: Amos is the prophet behind these words. His warnings are not only about ancient Israel. They press every generation to ask whether its worship is joined to mercy and fairness. Yet Amos also ends with hope, pointing to God's future restoration rather than leaving judgement as the final word (Amos 9:11).
But let judgment run down as waters, and righteousness as a mighty stream.