Methodism, also called the Methodist movement, is a group of historically related denominations of Protestant Christianity whose origins, doctrine and practice derive from the life and teachings of John Wesley. George Whitefield and John's brother Charles Wesley were also significant early leaders in the movement. They were named Methodists for "the methodical way in which they carried out their Christian faith". Methodism originated as a revival movement in the Church of England in the 18th century and became a separate denomination after Wesley's death. The movement spread throughout the British Empire, the United States, and beyond because of vigorous missionary work, and today has about 80 million adherents worldwide.

Wesleyan theology, which is upheld by the Methodist churches, focuses on sanctification and the transforming effect of faith on the character of a Christian. Distinguishing doctrines include the new birth, assurance, imparted righteousness, the possibility of entire sanctification, and the works of piety. Scripture is considered a primary authority, but Methodists also look to Christian tradition, including the historic creeds. Most Methodists teach that Jesus Christ, the Son of God, died for all of humanity and that salvation is available for all. This is an Arminian doctrine, as opposed to the Calvinist position, that God has pre-ordained the salvation of a select group of people. However, Whitefield and several other early leaders of the movement were considered Calvinistic Methodists and held to the Calvinist position.

The movement has a wide variety of forms of worship, ranging from high church to low church in liturgical usage, in addition to tent revivals and camp meetings held at certain times of the year. Denominations that descend from the British Methodist tradition are generally less ritualistic, while American Methodism is more so, the United Methodist Church in particular. Methodism is known for its rich musical tradition, and Charles Wesley was instrumental in writing much of the hymnody of Methodism.

In addition to evangelism, Methodism emphasizes charity and support for the sick, the poor, and the afflicted through the works of mercy. These ideals, the Social Gospel, are put into practice by the establishment of hospitals, orphanages, soup kitchens, and schools to follow Christ's command to spread the gospel and serve all people. Methodists are historically known for their adherence to the doctrine of nonconformity to the world, reflected by their traditional standards of a commitment to teetotalism, proscription of gambling, regular attendance at class meetings, and weekly observance of the Friday fast.

Early Methodists were drawn from all levels of society, including the aristocracy, but the Methodist preachers took the message to labourers and criminals who tended to be left outside organized religion at that time. In Britain, the Methodist Church had a major effect in the early decades of the developing working class (1760–1820). In the United States, it became the religion of many slaves, who later formed black churches in the Methodist tradition.