Vizhnitz is the name of a Hasidic dynasty founded by Rabbi Menachem Mendel Hager. Vizhnitz (ויז׳ניץ or וויזשניץ) is the Yiddish name of Vyzhnytsia, a town in present-day Ukraine (then, a village in Austrian Bukovina).
Followers of the rebbes of Vizhnitz are called Vizhnitzer Hasidim.