Kekristenan merupakan agama utama di [[Eropa]], [[Rusia]], [[Amerika]], [[Oseania]], Filipina, [[Indonesia]] Timur, [[Afrika Selatan]], [[Afrika Tengah]] dan [[Afrika Timur]].<ref>[http://www.britannica.com/eb/table?tocId=9394911 Encyclopædia Britannica] table of religions, by region; retrieved November 2007</ref> Terdapat juga komunitas Kristen besar di belahan dunia lainnya, seperti [[Tiongkok]], [[India]] dan [[Asia Tengah]], di mana Kekristenan menjadi agama terbesar kedua setelah [[Islam]]. [[Amerika Serikat]] adalah [[negara]] Kristen terbesar di dunia menurut populasi, yang disusul oleh [[Brasil]] dan [[Meksiko]].
Beberapa Kristen tak hanya mengimani, namun juga memiliki status resmi dalam sebuah [[agama negara]] dari negara-negara berikut: [[Armenia]] ([[Gereja Apostolik Armenia]]),<ref name="Armenian National Committee of America-Armenia">{{cite web|url = http://www.anca.org/press_releases/press_releases.php?prid=82|title = Gov. Pataki Honors 1700th Anniversary of Armenia's Adoption of Christianity as a state religion|publisher = Aremnian National Committee of America|accessdate = 2009-04-11|archive-date = 2010-06-15|archive-url = https://web.archive.org/web/20100615140846/http://anca.org/press_releases/press_releases.php?prid=82|dead-url = yes}}</ref> [[Costa Rica]] (Roman Catholic Church),<ref name="Encyclopædia Britannica-Costa Rica">{{cite web|url =http://www.britannica.com/EBchecked/topic/139528/Costa-Rica| title = Costa Rica|publisher = Encyclopædia Britannica|accessdate = 2008-05-11}}</ref> [[Denmark]] ([[Gereja Denmark]]),<ref name="Encyclopædia Britannica-Denmark">{{cite web|url =http://www.britannica.com/EBchecked/topic/157748/Denmark| title = Denmark|publisher = Encyclopædia Britannica|accessdate = 2008-05-11}}</ref> [[El Salvador]] (Gereja Katolik Roma),<ref name="Encyclopædia Britannica-El Salvador">{{cite web|url =http://www.britannica.com/EBchecked/topic/181798/El-Salvador| title = El Salvador|publisher = Encyclopædia Britannica|accessdate = 2008-05-11}}</ref> [[Inggris]] ([[Gereja Inggris]]),<ref name="Centre for Citizenship-England">{{cite web|url =http://www.centreforcitizenship.org/church1.html| title = Church and State in Britain: The Church of privilege|publisher = Centre for Citizenship|accessdate = 2008-05-11}}</ref> [[Georgia (negara)|Georgia]] ([[Gereja Ortodoks Georgia]]), [[Yunani]] ([[Gereja Yunani]]), [[Islandia]] ([[Gereja Islandia]]),<ref name="Encyclopædia Britannica-Iceland">{{cite web|url =http://www.britannica.com/EBchecked/topic/281235/Iceland|title = Iceland|publisher = Encyclopædia Britannica|accessdate = 2008-05-11}}</ref> [[Liechtenstein]] (Gereja Katolik Roma),<ref name="U.S. Department of State-Liechtenstein">{{cite web|url =http://www.state.gov/g/drl/rls/irf/2003/24418.htm|title = Liechtenstein|publisher = U.S. Department of State|accessdate = 2008-05-11}}</ref> [[Malta]] (Gereja Katolik Roma),<ref name="Encyclopædia Britannica-Malta">{{cite web|url =http://www.britannica.com/EBchecked/topic/360532/Malta|title = Malta|publisher = Encyclopædia Britannica|accessdate = 2008-05-11}}</ref> [[Monako]] (Gereja Katolik Roma),<ref name="Encyclopædia Britannica-Monaco">{{cite web|url =http://www.britannica.com/EBchecked/topic/388747/Monaco|title = Monaco|publisher = Encyclopædia Britannica|accessdate = 2008-05-11}}</ref> [[Rumania]] ([[Gereja Ortodoks Rumania]]), [[Norwegia]] ([[Gereja Norwegia]]),<ref name="Encyclopædia Britannica-Norway">{{cite web|url =http://www.britannica.com/EBchecked/topic/420178/Norway|title = Norway|publisher = Encyclopædia Britannica|accessdate = 2008-05-11}}</ref> [[Vatican City]] (Gereja Katolik Roma),<ref name="Encyclopædia Britannica-Vatican City">{{cite web|url =http://www.britannica.com/EBchecked/topic/623972/Vatican-City|title = Vatican|publisher = Encyclopædia Britannica|accessdate = 2008-05-11}}</ref> [[Swiss]] (Gereja Katolik Roma, [[Gereja Reformasi Swiss]] dan [[Gereja Kristen Katolik Swiss]]).
