Matrilineality in Judaism in the context of "Religious Jews"

"Who is a Jew?" (Hebrew: מיהו יהודי, romanized: mihu yehudi, pronounced [ˈmi(h)u je(h)uˈdi]), is a basic question about Jewish identity and considerations of Jewish self-identification. The question pertains to ideas about Jewish personhood, which have cultural, ethnic, religious, political, genealogical, and personal dimensions. Orthodox Judaism and Conservative Judaism follow Jewish law (halakha), deeming people to be Jewish if their mothers are Jewish or if they underwent a halakhic conversion. Reform Judaism and Reconstructionist Judaism accept both matrilineal and patrilineal descent as well as conversion. Karaite Judaism predominantly follows patrilineal descent as well as conversion.

Jewish identity is also commonly defined through ethnicity. Opinion polls have suggested that the majority of modern Jews see being Jewish as predominantly a matter of ancestry and culture, rather than religion.

As of 2025, the world's core Jewish population (those identifying as Jews to the exclusion of all else) was estimated at 15.8 million, which is approximately 0.2% of the 8 billion worldwide population. However, the "core Jewish" criterion faces criticism, especially in debates over the American Jewish population count, since it excludes the growing number of people who carry multiple ethnic and religious identities who may self-identify as Jews or qualify as Jewish under the Halakhic principle of matrilineal descent. Israel and the US host the largest Jewish populations of 7.42 million and 7.46 million respectively. Other countries with core Jewish populations above 100,000 include France (440,000), Palestine (432,800), Canada (398,000), the United Kingdom (312,000), Argentina (171,000), Russia (132,000), Germany (125,000), and Australia (117,200). In 1939, the core Jewish population reached its historical peak of 16.6 million or more. Due to the murder of almost six million Jews during the Holocaust, this number was reduced to 11 million by 1945. The core Jewish population grew to around 13 million by the 1970s and then recorded almost no growth until around 2005, due to low fertility rates and interfaith marriage by Jews. From 2005 to 2018, the world's core Jewish population grew 0.63% annually on average, while the world's population overall grew 1.1% annually in the same period. This increase primarily reflects rapid growth of Haredi, Orthodox populations.

"Who is a Jew?" (Hebrew: מיהו יהודי, romanized: mihu yehudi, pronounced [ˈmi(h)u je(h)uˈdi]) is a basic question about Jewish identity and considerations of Jewish self-identification. The question pertains to ideas about Jewish personhood, which have cultural, ethnic, religious, political, genealogical, and personal dimensions. Orthodox Judaism and Conservative Judaism follow Jewish law (halakha), deeming people to be Jewish if their mothers are Jewish or if they underwent a halakhic conversion. Reform Judaism and Reconstructionist Judaism accept both matrilineal and patrilineal descent as well as conversion. Karaite Judaism predominantly follows patrilineal descent as well as conversion.

Jewish identity is also commonly defined through ethnicity. Opinion polls have suggested that the majority of modern Jews see being Jewish as predominantly a matter of ancestry and culture, rather than religion.

Zera Yisrael (Hebrew: זרע ישראל, lit. 'Seed [of] Israel'), also known as Zera Kadosh (lit. 'Seed [of] Holiness'), is a legal category in Halakha that denotes the blood descendants of Jews who, for one reason or another, are not legally Jewish according to religious criteria. This is usually due to a lack of matrilineal Jewish ancestry.