As of 2017, there are about 1.8 billion Muslims in the world, according to the Pew Research Center; together, they make up nearly one-fourth of the world's population, making Islam the world's second largest religion after Christianity. Within the second half of this century, Muslims are expected to become the world's largest religious group. The Pew Research Center estimates that by 2070, Islam will overtake Christianity, due to faster birth rate (2.7 children per family vs. 2.2 for Christian families). As of 2017, Islam is the fastest growing religion in the world.

The Muslim population is a diverse community of believers spanning the globe. Over fifty countries have Muslim-majority populations, while other groups of believers are clustered in minority communities in nations on nearly every continent.

Although Islam is often associated with the Arab world and the Middle East, fewer than 15 percent of Muslims are Arab. By far, the largest populations of Muslims live in Southeast Asia (more than 60 percent of the world's total), while the countries of the Middle East and North Africa make up only 20 percent of the total. One-fifth of the world's Muslims live as minorities in non-Muslim countries, with the largest of these populations in India and China. While Indonesia currently has the largest population of Muslims, projections suggest that by 2050 India will have the world's largest population of Muslims, with estimates expected to reach at least 300 million.

Regional Distribution of Muslims (2017)

The largest Muslim populations are found in Southeast Asia, the Middle East, and North Africa.

Latin America/Caribbean: 840,000

North America: 3,480,000

Europe: 43,470,000

Subsaharan Africa: 248,420,000

Middle East/North Africa: 370,070,000

Asia/Pacific: 986,420,000

Countries With the Largest Muslim Populations (2017)

Although many people believe the largest Muslim populations are found in the Middle East, the countries with the most Muslims are actually found in South and Southeast Asia.

Indonesia: 209.1 million

Pakistan: 176.2 million

India: 167.4 million

Bangladesh: 134.4 million

Nigeria: 77.3 million

Egypt: 77 million

Iran: 73.6 million

Turkey: 71.3 million

Sudan: 39 million

Algeria: 34.7 million

Morocco: 31.9 million

Iraq: 31.2 million

The Spread of Islam Around the World

Islam began in the 7th century in Mecca, a city in present-day Saudi Arabia. Within 100 years, the first Islamic caliphate had taken control of the Middle East and North Africa. The Islamic Golden Age, a period that lasted from the 8th century to the 13th century, saw the expansion of the Muslim world into new territory, along with the establishment of trade routes. It was through trade that Islam was first introduced to Southeast Asia. Later, Sufi missionaries made deliberate efforts to spread the faith by blending Muslim ideas with local beliefs. Islam reached other continents, including North and South America, through immigration in the 19th and 20th centuries.

Muslims in America

After Christianity and Judaism, Islam is the third largest religion in the United States. However, Muslims still make up a relatively small portion of the population, at 1.1 percent. American Muslims include a large proportion of immigrants (58 percent of adult American Muslims), including many Asians. In general, American Muslims are one of the most racially diverse groups in the country, with a makeup that is 41 percent white, 20 percent black, 28 percent Asian, and 8 percent Hispanic.

As of 2014, the states with the greatest percentage of adult Muslims were New Jersey (3 percent), Arkansas (2 percent), District of Columbia (2 percent) and New York (2 percent). The city with the largest Muslim population in the United States is Dearborn, Michigan, with a population of 98,153, many of whom are immigrants from Syria, Iraq, and Yemen.

Since 2001, the year of the September 11 attacks on the World Trade Center, there has been a rise in Islamophobia in the United States, and in 2015 and 2016 there was a spike in the number of hate crimes committed against Muslims.