Wesleyan theology, otherwise known as Wesleyan–Arminian theology, or Methodist theology, is a theological tradition in Protestant Christianity based upon the ministry of the 18th-century evangelical reformer brothers John Wesley and Charles Wesley. More broadly it refers to the theological system inferred from the various sermons (e.g. the Forty-four Sermons), theological treatises, letters, journals, diaries, hymns, and other spiritual writings of the Wesleys and their contemporary coadjutors such as John William Fletcher, Methodism's systematic theologian.

In 1736, the Wesley brothers travelled to the Georgia colony in America as Christian missionaries; they left rather disheartened at what they saw. Both of them subsequently had "religious experiences", especially John in 1738, being greatly influenced by the Moravian Christians. They began to organize a renewal movement within the Church of England to focus on personal faith and holiness, putting emphasis on the importance of growth in grace after the New Birth. Unique to Wesleyan Methodism is its definition of sin: a "voluntary transgression of a known law of God." Methodist doctrine teaches that the life of a Christian subsequent to the New Birth should be characterized by holiness, living victoriously over sin. Calling it "the grand depositum" of the Methodist faith, John Wesley taught that the propagation of the doctrine of entire sanctification—the work of grace that enables Christians to be made perfect in love and be made free from the carnal nature—was the reason that God raised up the Methodists in the world.

Wesleyan–Arminian theology, manifest today in Methodism (inclusive of the Holiness movement), is named after its founders, John Wesley in particular, as well as for Jacobus Arminius, since it is a subset of Arminian theology. The Wesleys were clergymen in the Church of England, though the Wesleyan tradition places stronger emphasis on extemporaneous preaching, evangelism, as well as personal faith and personal experience, especially on the new birth, assurance, growth in grace, entire sanctification and outward holiness. In his Sunday Service John Wesley included the Articles of Religion, which were based on the Thirty-nine Articles of the Church of England, though stripped of their more peculiarly Calvinistic theological leanings. Wesleyan theology asserts the primary authority of Scripture and affirms the Christological orthodoxy of the first five centuries of church history.

Wesleyan–Arminianism developed as an attempt to explain Christianity in a manner unlike the teachings of Calvinism. Arminianism is a theological study conducted by Jacobus Arminius, from the Netherlands, in opposition to Calvinist orthodoxy on the basis of free will. In 1610, after the death of Arminius his followers, the Remonstrants led by Simon Episcopius, presented a document to the Netherlands. This document is known today as the Five Articles of Remonstrance. Wesleyan theology, on the other hand, was founded upon the teachings of John Wesley, an English evangelist, and the beliefs of this dogma are derived from his many publications, including his collected sermons, journal, abridgements of theological, devotional, and historical Christian works, and a variety of tracts and treatises on theological subjects. Subsequently, the two theories have joined into one set of values for the contemporary church; yet, when examined separately, their unique details can be discovered, as well as their similarities in ideals.

In the early 1770s, John Wesley, aided by the theological writings of John William Fletcher, emphasized Arminian doctrines in his controversy with the Calvinistic wing of the evangelicals in England. Then, in 1778, he founded a theological journal which he titled the Arminian Magazine. This period, during the Calvinist–Arminian debate, was influential in forming a lasting link between Arminian and Wesleyan theology.

Wesley's opposition to Calvinism was more successful than Arminius's, especially in the United States where Arminianism would become the dominant school of soteriology of Evangelical Protestantism, largely because it was spread through popular preaching in a series of Great Awakenings. Arminius's work was not a direct influence on Wesley. Yet, he chose the term "Arminianism" to distinguish the kind of Evangelicalism his followers were to espouse from that of their Calvinist theological opponents. Many have considered the most accurate term for Wesleyan theology to be "Evangelical Arminianism".

Wesley is remembered for visiting the Moravians of both Georgia and Germany and examining their beliefs, then founding the Methodist movement, which gave rise to a variety of Methodist denominations. Wesley's desire was not to form a new sect, but rather to reform the nation and "spread scriptural holiness" as truth. However, the creation of Wesleyan–Arminianism has today developed into a popular standard for many contemporary churches.

Methodism also navigated its own theological intricacies concerning salvation and human agency. In the 1830s, during the Second Great Awakening, critics accused the Holiness Movement of Pelagian teaching. Consequently, detractors of Wesleyan theology have occasionally unfairly perceived or labeled its broader thought. However, its core is recognized to be Arminianism.