Misnagdim (מתנגדים‎, "Opponents"; Sephardi pronunciation: Mitnagdim; singular misnaged / mitnaged) was a religious movement among the Jews of Eastern Europe which resisted the rise of Hasidism in the 18th and 19th centuries. The Misnagdim were particularly concentrated in Lithuania, where Vilnius served as the bastion of the movement, but anti-Hasidic activity was undertaken by the establishment in many locales. The most severe clashes between the factions took place in the latter third of the 18th century; the failure to contain Hasidism led the Misnagdim to develop distinct religious philosophies and communal institutions, which were not merely a perpetuation of the old status quo but often innovative. The most notable results of these efforts, pioneered by Chaim of Volozhin and continued by his disciples, were the modern, independent yeshiva and the Musar movement. Since the late 19th century, tensions with the Hasidim largely subsided, and the heirs of Misnagdim adopted the epithet Litvishe or Litvaks.

The rapid spread of Hasidism in the second half of the 18th century greatly troubled many traditional rabbis; many saw it as heretical. Much of Judaism was still fearful of the messianic movements of the Sabbateans and the Frankists, the followers of the messianic claimants Sabbatai Zevi (1626–1676) and Jacob Frank (1726–1791), respectively. Many rabbis suspected Hasidism of an intimate connection with these movements.

Hasidism's founder was Rabbi Israel ben Eliezer (c. 1700 – 1760), known as the Baal Shem Tov ("master of the good name"; usually applied to a saintly Jew who was also a wonder-worker), or simply by the acronym Besht (Hebrew: בעש"ט); he taught that man's relationship with God depended on immediate religious experience, in addition to knowledge and observance of the details of the Torah and Talmud.

The characteristically misnagdic approach to Judaism was marked by a concentration on highly intellectual Talmud study; however, it by no means rejected mysticism. The movement's leaders, like the Gaon of Vilna and Chaim of Volozhin, were deeply immersed in kabbalah. Their difference with the Hasidim was their opposition to involving mystical teachings and considerations in the public life, outside the elitist circles which studied and practiced kabbalah. The Hasidic leaders' inclination to rule in legal matters, binding for the whole community (as opposed to strictures voluntarily adopted by the few), based on mystical considerations, greatly angered the Misnagdim. On another theoretical level, Chaim of Volozhin and his disciples did not share Hasidism's basic notion that man could grasp the immanence of God's presence in the created universe, thus being able to transcend ordinary reality and potentially infuse everyday actions with spiritual meaning. However, Volozhin's exact position on the issue is subject to debate among researchers. Some believe the differences between the two schools of thought were almost semantic, while others regard their understanding of key doctrines as starkly different.

Lithuania became the heartland of the traditionalist opposition to Hasidism, so "Lithuanian" and "misnaged" became virtually interchangeable terms in popular perception. However, a sizable minority of Greater Lithuanian Jews belong(ed) to Hasidic groups, including Chabad, Slonim, Karlin-Stolin (Pinsk), Amdur and Koidanov.

The first documented opposition to the Hasidic movement was from the Jewish community in Shklow, Lithuania, in 1772. Rabbis and community leaders voiced concerns about the Hasidim because they were going to Lithuania. The rabbis sent letters forbidding Hasidic prayer houses, urging the burning of Hasidic texts, and humiliating prominent Hasidic leaders. The rabbis imprisoned the Hasidic leaders in an attempt to isolate them from coming into contact with their followers.

The excommunications against Hasidic Jews in 1772 was accompanied by the public destruction of early Hasidic pamphlets. The Vilna Gaon, Elijah ben Solomon Zalman, a prominent rabbi, galvanized opposition to Hasidic Judaism. He believed that the claims of miracles and visions made by Hasidic Jews were lies and delusions. A key point of opposition was that the Vilna Gaon maintained that greatness in Torah and Jewish religious observance must come through natural human efforts at Torah study without relying on any external "miracles" and "wonders". On the other hand, the Ba'al Shem Tov was focused on the emotional uplift of the Jewish people—especially following the Khmelnytsky Uprising (1648 – 1654) and the aftermath and disillusionment of the failed messiahships of Sabbatai Zevi and Jacob Frank. Opponents of Hasidism held that its followers viewed their rebbes idolatrously, if not as explicitly divine.

The Vilna Gaon expressed his disapproval of synagogues in which business was discussed and atheism openly believed, viewing them as disrespectful to sacred spaces. Other Jewish leaders criticized those claiming to be rabbis who did not honor Shabbat and mitzvot. Despite this, the Gaon encouraged the study of non-Jewish wisdom and opposed the assimilation of the Haskalah, aiming to enhance the spread of the Torah. It was noted that some who sought the role of rabbi did so out of a desire for power and recognition, a point often criticized in early Hasidism for lacking genuine pursuit of studying Torah for its own sake.