Malachi or Mal'achi (מַלְאָכִי "My messenger/angel", Standard Hebrew Malʾaḫi, Tiberian Hebrew Malʾāḵî) was a prophet in the Bible Old Testament and Jewish Tanakh.
He was the last of the minor prophets, and the writer of the Book of Malachi, the last book of the Old Testament canon (Mal. 4:4, 5, 6) Christian editions, and is the last book of the Neviim (prophets) section in the Jewish editions. No allusion is made to him by Ezra, however, and he does not mention the restoration of the temple, and hence it is inferred that he prophesied after Haggai and Zechariah (Mal. 1:10; 3:1, 10). It is probable that he delivered his prophecies about 420 BCE, after the second return of Nehemiah from Persia (Neh. 13:6), or possibly before his return. Compare Mal. 2:8 with Neh. 13:15; Mal. 2:10-16 with Neh. 13:23).
The name is not a "nomen proprium"; it is generally assumed to be an abbreviation of ("messenger of Yhwh"), which conforms to the Μαλαχίας of the Septuagint and the "Malachias" of the Vulgate. The Septuagint superscription is ὲν χειρὶ ἀγγήλου αὐτοῦ, for .
Wellhausen, Abraham Kuenen, and Wilhelm Gustav Hermann Nowack consider ch. i. 1 a late addition, pointing to Zech. ix. 1, xii. 1. Carl Heinrich Cornill states that Zech. ix.-xiv. and Malachi are anonymous, and were, therefore, placed at the end of the prophetical books. Mal. iii. 1 shows almost conclusively that the term was misunderstood, and that the proper name originated in a misconception of the word. The consensus of opinion seems to point to 432-424 BCE as the time of the composition of the book. This was the time between the first and second visits of Nehemiah to Jerusalem. Some assert that the book was written before 458 BCE, that is, before the arrival of Ezra in Jerusalem.