Haredi (Hebrew: חֲרֵדִי Ḥaredi, IPA: [χaʁeˈdi]), or Charedi/Chareidi Judaism (pl. Haredim) is a term used to describe the most conservative form of Orthodox Judaism, often referred to by outsiders as ultra-Orthodox. Haredi Jews, like other Orthodox Jews, consider their belief system and religious practices to extend in an unbroken chain back to Moses and the giving of the Torah on Mount Sinai. As a result, they regard non-Orthodox, and to an extent Modern Orthodox, streams of Judaism to be deviations from authentic Judaism. Its historical rejection of Jewish secularism distinguishes it from Western European-derived Modern Orthodox Judaism.
Haredi Judaism is not an institutionally cohesive or homogeneous group, but comprises a diversity of spiritual and cultural orientations, generally divided into a broad range of Hasidic sects, Lithuanian-Yeshivish streams from Eastern Europe, and Oriental Sephardic Haredim.
Haredim are currently primarily located in Israel, North America and Western Europe. The population is growing very rapidly, due to high birth rate, and doubles every 12 to 20 years. Estimates of the number of Haredim globally are difficult to measure, due to its imprecise definition, lack of data collection and rapid change over time. One newspaper article estimated there were approximately 1.3 million Haredi Jews as of 2011. The Haredi community has gained growing media interest recently, in particular on the issue of sex segregation in Israel] and New York.