The U.S. government estimates the total population at 23.6 million (midyear 2021).  According to a survey by the Academia Sinica’s Institute of Sociology released in 2019, 49.3 percent of the population exclusively practices traditional folk religions, 14 percent Buddhism, and 12.4 percent Taoism, with 13.2 percent identifying as nonbelievers.  The rest of the population consists mainly of Protestants (5.5 percent), I-Kuan Tao (2.1 percent), Catholics (1.3 percent), and other religious groups, including Jews, Sunni Muslims, Tien Ti Chiao (Heaven Emperor Religion), Tien Te Chiao (Heaven Virtue Religion), Li-ism, Hsuan Yuan Chiao (Yellow Emperor Religion), Tian Li Chiao (Tenrikyo), Pre-cosmic Salvationism, Church of Scientology, the Baha’i Faith, Jehovah’s Witnesses, the Mahikari, The Church of Jesus Christ of Latter-day Saints, and the Family Federation for World Peace and Unification (Unification Church).

Some studies found that as many as 80 percent of religious practitioners combine multiple faith traditions.  Many adherents consider themselves both Buddhist and Taoist, and many individuals also incorporate some aspects of traditional folk religions, such as shamanism, ancestor worship, and animism, into their belief in Buddhism, Taoism, Confucianism, or other religions.  Some practitioners of Buddhism, Taoism, and other religions also practice Falun Gong, a self-described spiritual discipline.  According to the Falun Gong Society of Taiwan, Falun Gong practitioners number in the hundreds of thousands.

According to 2021 MOL statistics and the Council of Indigenous Peoples, the majority of the indigenous population of 580,000 is Protestant or Roman Catholic.  There are an estimated 695,000 foreign workers, primarily from Southeast Asia.  The largest group of foreign workers is from Indonesia, consisting of approximately 247,000 persons, who are predominantly Muslim.  The second largest group of workers is from Vietnam, consisting of approximately 243,000 persons, who are predominantly Buddhist.  Workers from the Philippines – numbering approximately 146,000 persons – are predominantly Roman Catholic.