Religion in Turkey consists of various religious beliefs. While Turkey is officially a secular state, numerous surveys all show that Islam is the country's most common religion. According to the state, 99.8% of the population is initially registered as Muslim. The remaining 0.2% are Christians and adherents of other officially recognised religions such as Judaism. However, because the government registers everyone as Muslim at birth by default, the official statistics can be misleading. There are many people who follow other religions or do not adhere to any religion, yet they are officially classified as 'Muslim' in official records unless they make a contrary claim. These records can be changed or even blanked out on the request of the citizen using a valid electronic signature to sign the electronic application. According to a 2025 report from Pew Research Center, 95% of Turkey self-identified as Muslim. A significant percentage of those are non-observing Cultural Muslims.
Turkey has officially been a secular country since its 1924 constitution was amended in 1928. This was later strengthened and entrenched with the wider appliance of laicism by founder Atatürk during the mid-1930s, as part of the Republican reforms. Strict regulations on religion, including a ban on Islamic attire, were imposed. The rights of Armenian Apostolic, Greek Orthodox, and Jewish citizens were recognized under the Treaty of Lausanne.
