The number depends on the definition. Pew Research Center’s latest global religious landscape analysis reports that Muslims were a majority in 53 countries and territories in 2020. The Organisation of Islamic Cooperation, by contrast, has 57 member states—but OIC membership is a political category, not a list of Muslim-majority countries.
Pew’s demographic count
Pew’s recent global analysis, based on thousands of censuses and surveys, found no change from 2010 to 2020 in the number of places where Muslims formed a majority: 53.
That count includes countries and territories covered by the study and uses population data rather than constitutional labels such as Islamic republic.
Why the OIC number is 57
The Organisation of Islamic Cooperation describes itself as an intergovernmental organization with 57 member states. Most have Muslim-majority populations, but membership and demography are not identical concepts.
Political membership reflects history, diplomacy, and institutional criteria rather than a single population threshold.
Muslims also live as minorities
Large Muslim populations live in countries where Muslims are not the majority, including India and several other major states.
For that reason, counting Muslim-majority countries does not tell us where all Muslims live or which countries have the largest Muslim populations.
Global Muslim population growth
Pew estimates that the worldwide Muslim population grew rapidly from 2010 to 2020, reaching roughly a quarter of humanity. Much of that increase reflects the young age structure and population growth in countries where Muslims are concentrated.
Population share can change without any country crossing the 50% majority threshold.
Current answer
For demographic purposes, Pew’s latest global study identifies 53 Muslim-majority countries and territories as of 2020. The OIC has 57 member states, which is a different measure.
