The Hebrew alphabet (aleph-bet) (Alef Beis) (Hebrew: אָלֶף-בֵּית עִבְרִי‎, alephbet ivri) consists of 22 letters used for writing the Hebrew language and, in mildly adapted forms, for writing several languages of the Jewish diaspora, most famously Yiddish, Ladino, and Judeo-Arabic (for a full and detailed list, see Jewish languages). Five of these letters have a different form when appearing as the last letter in a word. Hebrew is written from right to left.

The Hebrew word for "alphabet" is אלפבית (alephbet), named after the first two letters of the Hebrew alphabet (Aleph, Bet). The Hebrew alphabet is an abjad, having letters only for consonants, but means were later devised to indicate vowels by separate vowel points or niqqud. In rabbinic Hebrew, the consonant letters אהוי are used as matres lectionis to represent vowels.

The number of letters in the Hebrew alphabet, their order, their names, and their phonetic values are virtually identical to those of the Aramaic alphabet, as both Hebrews and Arameans borrowed the Phoenician alphabet for their uses during the end of the 2nd millennium BCE.

According to contemporary scholars, the modern script used for writing Hebrew (usually called the Jewish script by scholars, and also traditionally known as the square script, block script, or Assyrian script — not to be confused with the Eastern variant of the Syriac alphabet) evolved during the 3rd century BCE from the Aramaic script, which had been used by Jews for writing Hebrew since the 6th century BCE, retaining the old script only for the Name of God. Prior to that, Hebrew was written using the old Hebrew script, which evolved during the 10th century BCE from the Phoenician script; the Samaritans still write Hebrew in a variant of this script for religious works (see Samaritan alphabet). For other opinions, see below.