The U.S. government estimates the total population at 29.8 million (midyear 2020 estimate). More than 99 percent of the population is Muslim (2010 estimate), associating their beliefs with either the Shafi’i order of Sunni Islam or Zaydi Islam, a distinct form of Shia Islam. There are also significant numbers of Sunni followers of the Maliki and Hanbali schools, and significant numbers of Ismaili and Twelver followers of Shia Islam. While there are no official statistics, the U.S. government estimates 65 percent of the population is Sunni and 35 percent Zaydi. Baha’is, Jews, Hindus, and Christians, many of whom are refugees or temporary foreign residents, comprise less than 1 percent of the population. Christian groups include Roman Catholics and Anglicans. According to the UN Group of Experts, many Ethiopian and Eritrean Christian economic migrants transit the country on their way to find work in Saudi Arabia, making the total number of Christians subject to fluctuation.

There is no firm estimate of the number of persons of Indian origin or of those who practice Hinduism, Sikhism, or the Dawoodi Bohra variant of Ismaili Shia Islam residing in the country. The preconflict Hindu population was 150,000 (2010 estimate), concentrated in Aden, Mukalla, Shihr, Lahaj, Mokha, and Hudayah. According to one source, the current number of Indian nationals is fewer than 3,000. Many members of the Indian-origin community have resided in the country for generations and hold Yemeni nationality.

The Jewish community is an indigenous non-Muslim minority religious group. Reports estimate approximately 20 to 40 Jews remain, concentrated in Sana’a and Raydah, in Amran Governorate north of Sana’a.