Tidak beragama merupakan istilah yang merujuk kepada ketiadaan pegangan agama.[2] Menurut konteks, tidak beragama dapat dimaksudkan sebagai atheisme, deisme, nonteisme, agnostisisme, ignostisisme, anti agama, skeptisisme, atau humanisme sekular.
The Religiosity Index is a measure of the importance of religion for respondents and their self-reported attendance of religious services. For religions in which attendance at services is limited, care must be used in interpreting the data. (Gallup WorldView)
"Global Index Of Religion and Atheism"(PDF). Redcresearch.ie. Diarkibkan daripada yang asal(PDF) pada 2012-10-16. Dicapai pada 2011-11-01.line feed character in |title= at position 16 (bantuan) Publications are taken from Gallup