Islam by country

Adherents of Islam constitute the world's second largest religious group. A projection by the PEW suggests that Muslims numbered approximately 1.9 billion followers in 2020. Studies in the 21st century suggest that, in terms of percentage and worldwide spread, Islam is the fastest-growing major religion in the world, mostly because Muslims have more children than other major religious groups. Most Muslims are either of two denominations: Sunni (87–90%, roughly 1.7 billion people) or Shia (10–13%, roughly 180–230 million people). Islam is the majority religion in several subregions: Central Asia, Western Asia, North Africa, West Africa, the Sahel, and the Middle East. The diverse Asia-Pacific region contains the highest number of Muslims in the world, surpassing the combined Middle East and North Africa.

According to the Pew Research Center in 2010, there were 50 Muslim-majority countries. Around 62% of the world's Muslims live in the Asia-Pacific region (from Turkey to Indonesia), with over one billion adherents. According to the Pew Research Center in 2017, the largest Muslim population in a country is in Indonesia, a country home to 12.7% of the world's Muslims, followed by Pakistan (11.1%), India (10.9%) and Bangladesh (9.2%).

About 20% of Muslims live in the Arab world. In the Middle East, Iran and Turkey are the largest Muslim-majority countries, while Egypt and Nigeria in Africa have the same status.