The Bible Belt is an informal region in the southeastern and south-central United States in which socially conservative evangelical Protestantism plays a strong role in society and politics, and Christian church attendance across the denominations is generally higher than the nation's average. During the colonial period (1607–1776), the South was a stronghold of the Anglican church. Its transition to a stronghold of non-Anglican Protestantism occurred gradually over the next century as a series of religious revival movements, many associated with the Baptist denomination, gained great popularity in the region.
The region is usually contrasted with the religiously diverse Midwest and Great Lakes, the Mormon Corridor in Utah and southern Idaho, and the relatively secular Western and Northeastern United States. Whereas the state with the highest percentage of residents identifying as non-religious is the New England state of Vermont at 37%, in the Bible Belt state of Alabama it is just 12%. Tennessee has the highest proportion of Evangelical Protestants, at 52%. The earliest known usage of the term "Bible Belt" was by American journalist and social commentator H. L. Mencken, who in 1924 wrote in the Chicago Daily Tribune: "The old game, I suspect, is beginning to play out in the Bible Belt." Mencken claimed the term as his invention in 1927.
The name "Bible Belt" has been applied historically to the South and parts of the Midwest, but is more commonly identified with the South. In a 1961 study, Wilbur Zelinsky delineated the region as the area in which Protestant denominations, especially Southern Baptist, Methodist, and evangelical, are the predominant religious affiliation. The region thus defined included most of the Southern United States, including most of Texas and Oklahoma, and in the states south of the Ohio River, and extending east to include central West Virginia and Virginia, from the Rappahannock River southward. In addition, the Bible Belt covers most of Missouri and Kentucky and southern parts of Illinois, Indiana, and Ohio. On the other hand, areas in the South which are not considered part of the Bible Belt include heavily Catholic Southern Louisiana, central and southern Florida, which have been settled mainly by immigrants and Americans from elsewhere in the country, and overwhelmingly Hispanic South Texas. A 1978 study by Charles Heatwole identified the Bible Belt as the region dominated by 24 fundamentalist Protestant denominations, corresponding to essentially the same area mapped by Zelinsky.
According to Stephen W. Tweedie, an Associate Professor Emeritus in the Department of Geography at Oklahoma State University, the Bible Belt is now viewed in terms of numerical concentration of the audience for religious television. He finds two belts: one more eastern that stretches from Florida, (excluding Miami, Tampa and South Florida), through Alabama, Tennessee, Kentucky, Georgia, North and South Carolina, and into Southern Virginia ; and another that concentrated in Texas (excluding El Paso, and South Texas), Arkansas, Louisiana, (excluding New Orleans and Acadiana), Oklahoma, Missouri (excluding St. Louis), Kansas, and Mississippi. "[H]is research also broke the Bible Belt into two core regions, a western region and an eastern region. Tweedie's western Bible Belt was focused on a core that extended from Little Rock, Arkansas to Tulsa, Oklahoma. His eastern Bible Belt was focused on a core that included the major population centers of Virginia and North Carolina.
A study was commissioned by the American Bible Society to survey the importance of the Bible in the metropolitan areas of the United States. The report was based on 42,855 interviews conducted between 2005 and 2012. It determined the 10 most "Bible-minded" cities were Knoxville, Tennessee; Shreveport, Louisiana; Chattanooga, Tennessee; Birmingham, Alabama; Jackson, Mississippi; Springfield, Missouri; Charlotte, North Carolina;, Lynchburg, Virginia; Huntsville-Decatur, Alabama; and Charleston, West Virginia.
In addition to the South, there is a smaller Bible Belt in West Michigan, centered around the heavily Dutch-influenced cities of Holland and Grand Rapids. Christian colleges in that region include Calvin College, Hope College, Cornerstone University, Grace Bible College, and Kuyper College. West Michigan is generally fiscally and socially conservative.
Several locations are occasionally referred to as "the Buckle of the Bible Belt":
There has been research that links evangelical Protestantism with social conservatism. In 1950, President Harry S. Truman told Catholic leaders he wanted to send an ambassador to the Vatican. Truman said the leading Democrats in Congress approved, but they warned him, "it would defeat Democratic Senators and Congressmen in the Bible Belt."
In presidential elections, the Bible Belt states of Alabama, Mississippi, South Carolina, and Texas have voted for the Republican candidate in all elections since 1980; Oklahoma has supported the Republican presidential candidate in every election since 1968. Other Bible Belt states have voted for the Republican presidential candidate in the majority of elections since 1980, but have gone to the Democratic candidate either once or twice since then. However, with the exception of Mississippi, historical geographer Barry Vann shows that counties in the upland areas of the Appalachians and the Ozarks have a more conservative voting pattern than the counties located in the coastal plains.
Toowoomba city in Queensland has long been regarded as fertile ground for Christian fundamentalist religio-political right-wing movements  that adhere to biblical literalism, particularly those within the Pentecostal and charismatic stream of Christianity. This was exemplified by the highly publicised rise and subsequent fall of Howard Carter and the Logos Foundation in the 1980s. The Logos Foundation and other similar movements that have followed it, operate in a controlling, authoritarian and almost cultish manner, contributing to their notoriety. Other similarly conservative Pentecostal churches within the city have, since that time, banded together into a loose federation known as the Toowoomba Christian Leaders' Network. (note - most traditional church denominations have their own, separate ecumenical group) This network, views itself as having a divine mission to 'take the city for the Lord' and as such, endorses elements of religious right-wing political advocacy, such as the Australian Christian Lobby(ACL). ACL's current managing director who was raised in the Logos Foundation and is a former Toowoomba City councilor, is Lyle Shelton. These church groups are strongly associated with North American trends such as the New Apostolic Reformation, Dominion theology, Five-fold ministry thinking, Kingdom Now theology and revivalism. They support the achievement of a type of theocratic society where conservative and literal interpretations of the bible are the dominant drivers of government, education, the Arts, the media and entertainment. Churches involved in this group currently include the successor organization to the Logos Foundation, the Toowoomba City Church, along with the Range Christian Fellowship, Spring Street Assembly of God, Christian Outreach Centre, Hume Ridge Church of Christ, Revival Ministries of Australia Shiloh Centre, the Edge Christian Centre and many others.
The area normally called the Bible Belt of Sweden is centered on Jönköping in southern Sweden and contains numerous free churches. There are also numerous conservative Lutheran Laestadians in the Torne valley area in the far north of the country.
An area in Erzgebirge in Saxony has been described also as the "Saxon Bible Belt" with a notable evangelical Protestant/Christian fundamentalist/free church community, as well as some conservative Lutheran parishes that are opposed to homosexual marriage. Nevertheless, the Evangelical-Lutheran Church of Saxony approved church resolutions regarding the issue regardless of opinions within those parishes.
In New Zealand, Mount Roskill, Auckland, contains the highest number of churches per capita in the country, and is the home of several Christian political candidates. The electorate was one of the last in the country to go "wet", in 1999, having formerly been a dry area where the selling of alcohol was prohibited.
At the 2013 New Zealand census, the Mangere–Otahuhu local board area of Auckland had the highest concentration of Christians in New Zealand, with 67.7 percent of the local board's 71,000 residents identifying as so.
In Northern Ireland, the area in County Antrim stretching from roughly Ballymoney to Larne and centred in the area of Ballymena is often referred to as a Bible Belt. This is because the area is heavily Protestant with a large evangelical community. From 1970 to 2010, the MP for North Antrim was Ian Paisley, a Free Presbyterian minister well known for his theological fundamentalism. The town of Ballymena, the largest town in the constituency, is often referred to as the "buckle" of the Bible Belt. In the Republic of Ireland, County Wicklow and western parts of County Cork have the highest population of Protestants.