Jewish languages are the various languages and dialects that developed in Jewish communities in the diaspora. The original Jewish language is Hebrew, supplanted as the primary vernacular by Aramaic following the Babylonian exile. Jewish languages feature a syncretism of Hebrew and Judeo-Aramaic with the languages of the local non-Jewish population.

Early Northwest Semitic (ENWS) materials are attested through the end of the Bronze Age—2350 to 1200 BCE. At this early state, Biblical Hebrew was not highly differentiated from the other Northwest Semitic languages (Ugaritic and Amarna Canaanite), though noticeable differentiation did occur during the Iron Age (1200–540 BCE). Hebrew as a separate language developed during the latter half of the second millennium BCE between the Jordan River and the Mediterranean Sea, an area known as Canaan.

The earliest distinctively Hebrew writing yet discovered was found at Khirbet Qeiyafa and dates to the 10th century BCE. The Israelite tribes established a kingdom in Canaan at the beginning of the first millennium BCE, which later split into the Kingdom of Israel in the north and the Kingdom of Judah in the south after a dispute of succession.

The kingdom of Israel was destroyed by the Assyrians in 722 BCE, and the kingdom of Judah was conquered by the Babylonians in 586 BCE, its higher classes exiled and the first Temple destroyed. Aramaic became the primary language of the Jews deported to Babylonia, with the first attestations of Jewish/Judean Aramaic found in scrolls from the 5th century BCE on the island of Elephantine. Later the Persians made Judah a province and permitted Jewish exiles to return and rebuild the Temple. Aramaic became the common language in the north of Israel, in Galilee and Samaria, though Hebrew remained in use in Judah with Aramaic influence.

Alexander the Great conquered Judah in 332 BCE, beginning the period of Hellenistic domination. During the Hellenistic period Judea became independent under the Hasmoneans, but later the Romans ended their independence, making Herod the Great their governor. One Jewish revolt against the Romans led to the destruction of the Second Temple in 70 CE, and the second Bar-Kochba revolt in 132–135 CE led to a large departure of the Jewish population of Judea. Biblical Hebrew after the Second Temple period evolved into Mishnaic Hebrew, which ceased being spoken and developed into a literary language around 200 CE. Hebrew remained in widespread use among diasporic communities as the medium of writing and liturgy, forming a vast corpus of literature which includes rabbinic, medieval, and modern literature prior to the revival of Hebrew as a spoken language.

Jewish communities were dispersed around the world in the diaspora which followed the Jewish-Roman wars. Some adopted the languages of their neighbors, but many developed new varieties of these languages, collectively termed "Jewish languages". Various reasons led to the development of distinctive Jewish varieties of the languages of their non-Jewish host populations. Jews have often had limited exposure to non-Jewish society for various reasons, including imposed ghettoization (whether self-imposed separation or the forced creation of the ghetto by the host city) and strict endogamy, and as a result, Jewish languages diverged and developed separately from non-Jewish varieties in the territories they settled in. Due to frequent expulsions and migrations, single Jewish communities were often influenced by multiple distinct regional languages via language contact. For example, Yiddish, while based on Middle High German, has elements of Romance and Slavic. Jewish languages belong to a variety of genealogical language families, but these languages have common characteristics, making their study a distinct field of comparative linguistics known as Jewish linguistics.

The common feature between the Jewish languages is the presence of Hebrew and Judeo-Aramaic lexical components, stemming from the shared use of these languages in writing and liturgy. Many Jewish languages also display phonological, morphological, and syntactic features distinct from their non-Jewish counterparts. Most written Jewish languages are Hebraized, meaning they use a modified version of the Hebrew alphabet. These languages, unless they already have an accepted name (i.e. Yiddish, Ladino), are prefixed with "Judeo" (e.g. Judeo-Italian, Judeo-Arabic, Judeo-Persian, Judeo-Aramaic, Judeo-Marathi, Judeo-Malayalam, etc). Bukharan Jews spoke Bukhori, a dialect of Tajik, and Mountain Jews spoke Judeo-Tat.

In the early 20th century, secularism among Jews and large population shifts prompted the beginning of a shift from Jewish to non-Jewish languages. Even so, the majority of Jews in Eurasia and Africa, and many immigrants in North America and Palestine, still spoke Jewish languages. However, the Holocaust brought about a significant drop in the use of Jewish languages, especially Yiddish. Later, especially since the COVID-19 pandemic, learning Yiddish has begun to see a significant increase in popularity and interest, with studies revealing a surge in registration to online Yiddish language learning resources.