The KJV mentions unicorns nine times

The nine occurrences in the KJV

The word “unicorn” or “unicorns” appears in the King James Version at:

In each case, the underlying Hebrew is the same word — רְאֵם (re’em) — appearing in singular or plural forms.

What re’em refers to

HALOT s.v. re’em identifies the word with the wild ox — specifically with the aurochs (Bos primigenius), an enormous wild bovine that ranged across Europe, the Near East, and parts of Asia and North Africa in antiquity. The aurochs is the wild ancestor of modern domestic cattle.

The aurochs was a substantial animal — males stood up to 1.8 meters (6 feet) at the shoulder, with long forward-curving horns. It was hunted in antiquity, depicted in cave paintings (Lascaux, c. 17,000 BC), and survived in dwindling populations across Europe until the seventeenth century. The last aurochs is recorded as having died in 1627 in the Jaktorów Forest in Poland.

In the Hebrew Bible, re’em appears in contexts that emphasise the animal’s strength and untameable wildness — exactly what one would expect of a description of a wild ox:

• Numbers 23:22 — strength, in a description of God’s power to bring Israel out of Egypt
• Job 39:9-10 — the LORD’s challenge to Job, asking whether Job can domesticate the re’em. The point is precisely that the animal is untameable. (Job 39 in general is a passage about untamable wild creatures.)
• Psalm 92:10 — “my horn shalt thou exalt like the horn of an unicorn / wild ox” — using the horn as a symbol of strength

How the KJV got “unicorn”

The KJV’s choice of “unicorn” reflects the translation history:

The Septuagint

When the Hebrew Bible was translated into Greek (the Septuagint, third to second century BC), re’em was rendered as μονοκέρως (monokerōs) — “one-horned” — in many places. This reflects the Greek translators’ interpretation of re’em (or perhaps an Egyptian-Hellenistic association with the rhinoceros, an animal that is single-horned and powerful).

The Vulgate

When Jerome translated the Latin Vulgate (late fourth century AD), he rendered the Septuagint’s monokerōs as unicornis in some passages and rhinoceros in others. Unicornis is a literal Latin translation of the Greek (uni- = “one,” cornis = “horn”). At Numbers 23:22 specifically, Jerome used rhinoceros — the Greek word for the African and Asian rhinoceros species, which Jerome would have known were single-horned and powerful.

The KJV (1611)

The KJV translators worked from the Hebrew text but were heavily influenced by the Latin Vulgate’s translation tradition. They rendered re’em as “unicorn” — following Jerome’s unicornis — across the nine occurrences. The translators were not asserting the existence of a magical horse-with-a-horn creature; they were using the English word “unicorn” in its sixteenth-century sense, which carried a wider range — covering rhinoceroses, single-horned legendary beasts, and wild oxen with prominent horns. The English of the KJV is often more generous in its categories than modern readers assume.

Subsequent translations

The Revised Version (1885) replaced “unicorn” with “wild ox” throughout. The American Standard Version (1901), the RSV (1952), the NIV (1978), the ESV (2001), and most modern translations have followed this revision. The BSB and NRSV both render re’em as “wild ox.”

The mythological unicorn

The mythological unicorn — a horse-like creature with a single spiral horn, associated with purity and capturable only by a virgin — is a separate cultural figure. It develops in medieval European literature and art, with antecedents in classical Greek and Latin descriptions of monokerōs (the same Greek word used in the Septuagint).

Whether the medieval unicorn legend draws partly on the biblical KJV usage, or whether the Greek translators of the Septuagint were using a word that already had mythological resonance, is a question of cultural and translation history. The lexical situation in Hebrew is clear: re’em refers to the aurochs.

What this entry does not do

We do not say the KJV translators were wrong. They were translating the underlying Hebrew using the best lexical resources of their time, which followed the Septuagint and Vulgate traditions. Subsequent zoological and lexical scholarship has refined the identification of re’em with the aurochs; modern translations reflect that refinement.

The unicorn-as-mythological-horse-creature is a separate phenomenon. The KJV’s “unicorn” referred to a specific real animal in its own translators’ usage; that animal is now identified with the aurochs.