Mennonites are groups of Anabaptist Christian church communities of denominations. The name is derived from the founder of the movement, Menno Simons (1496–1561) of Friesland. Through his writings about Reformed Christianity during the Radical Reformation, Simons articulated and formalized the teachings of earlier Swiss founders, with the early teachings of the Mennonites founded on the belief in both the mission and ministry of Jesus, which the original Anabaptist followers held with great conviction, despite persecution by various Roman Catholic and Mainline Protestant states. Formal Mennonite beliefs were codified in the Dordrecht Confession of Faith in 1632, which affirmed "the baptism of believers only, the washing of the feet as a symbol of servanthood, church discipline, the shunning of the excommunicated, the non-swearing of oaths, marriage within the same church", strict pacifistic physical nonresistance, anti-Catholicism and in general, more emphasis on "true Christianity" involving "being Christian and obeying Christ" however they interpret it from the Holy Bible.

The majority of the early Mennonite followers, rather than fighting, survived by fleeing to neighboring states where ruling families were tolerant of their belief in believer's baptism. Over the years, Mennonites have become known as one of the historic peace churches, due to their commitment to pacifism.

Congregations worldwide embody the full scope of Mennonite practice, from Old Order Mennonites (who practice a lifestyle without certain elements of modern technology) to Conservative Mennonites (who hold to traditional theological distinctives, wear plain dress and use modern conveniences) to mainline Mennonites (those who are indistinguishable in dress and appearance from the general population). Mennonites can be found in communities in 87 countries on six continents. Seven ordinances have been taught in many traditional Mennonite churches, which include "baptism, communion, footwashing, marriage, anointing with oil, the holy kiss, and the prayer covering." The largest populations of Mennonites are found in Canada, the Democratic Republic of the Congo, Ethiopia, India, and the United States. There are Mennonite colonies in Argentina, Belize, Bolivia, Brazil, Mexico, Peru, Uruguay, Paraguay, and Colombia. The Mennonite Church in the Netherlands still continues where Simons was born.

Though Mennonites are a global denomination with church membership from Europe, Asia, Africa and the Americas, certain Mennonite communities with ethno-cultural origins in Switzerland and the Netherlands bear the designation of ethnic Mennonites.