Christian democracy is a political ideology that emerged in 19th-century Europe under the influence of Catholic social teaching and neo-Calvinism.

It was conceived as a combination of modern democratic ideas and traditional Christian values, incorporating social justice and the social teachings espoused by the Catholic, Lutheran, Reformed, Pentecostal, and other denominational traditions of Christianity in various parts of the world.

After World War II, Catholic and Protestant movements of neo-scholasticism and the Social Gospel shaped Christian democracy.

On the European left-right political spectrum Christian Democracy has been difficult to pinpoint as Christian democrats rejected liberal economics and individualism and advocated state intervention, but simultaneously defended private property rights against excessive state intervention. This has meant that Christian Democracy has historically been considered centre-left on economics and centre-right on many social, and moral issues. More recently, Christian Democrats have positioned themselves as the centre-right, such as the European People's Party, with which most European Christian democratic parties are affiliated, identifies itself as being "the EU's centre-right party". Christian democrats support a "slightly regulated market economy", featuring an effective social security system, a model also known as a social market economy.

Worldwide, many Christian democratic parties are members of the Centrist Democrat International. Examples of major Christian democratic parties include the Christian Democratic Union of Germany, the Dutch Christian Democratic Appeal, the Centre in Switzerland, the Spanish People's Party, the Mexican National Action Party, the Austrian People's Party, and the Christian Democratic Party of Chile. Of these parties, only the Chilean one is centre-left, with the remaining ones ranging from the centre to the right-wing.

Christian democracy continues to be influential in Europe and Latin America, although it is also present in other parts of the world. Many European Christian democratic parties are affiliated with the European People's Party. Compared to the pro-European EPP, those with Eurosceptic views may be members of the European Christian Political Movement. Many Christian democratic parties in the Americas are affiliated with the Christian Democrat Organization of America.