The Presbyterian Church of Wales (Welsh: Eglwys Bresbyteraidd Cymru), also known as the Calvinistic Methodist Church (Yr Eglwys Fethodistaidd Galfinaidd), is a denomination of Protestant Christianity based in Wales.

The Calvinistic Methodist movement has its origins in the 18th-century Welsh Methodist revival. The early movement was led principally by Welsh revivalist Daniel Rowland, who was influenced by the teachings of the Welsh Methodist leader Howell Harris and the theologian John Calvin. As such, Calvinistic Methodism places a strong emphasis on the sovereignty of God and the Calvinist doctrine of predestination.

The movement had a profound impact on Welsh society and culture, and it played a significant role in the Welsh revivals of the 19th century. Calvinistic Methodism formerly also had a significant presence in England, under the spiritual leadership of George Whitefield. Today, the large majority of the Presbyterian Church of Wales' congregations are in Wales (predominantly Welsh-speaking, but some English), but it also has a few local churches in the west of England (English-speaking).

The church was born as the Calvinistic Methodists out of the Welsh Methodist revival and the preaching of Howell Harris and Daniel Rowland in the 18th century and seceded from the Church of England in 1811. Calvinistic Methodism became a major denomination in Wales, growing rapidly in the 19th century, and taking a leadership role in the Welsh Religious Revival of 1904–05. In 1823, a Confession of Faith was created and adopted, based on the standard Westminster Confession. Theological colleges for ministerial training were opened in Bala, then in Merionethshire, now Gwynedd (1837), Trefeca, then in Brecknockshire, now Powys (1842), and Aberystwyth, in Ceredigion (1906). It produces a quarterly journal Y Traethodydd and a monthly periodical The Treasury. It is distinguished from other forms of Methodism by the Calvinistic nature of its theology. In 1840, the Foreign Missionary Society was formed in Liverpool to provide missionaries to India. It held its first general assembly in 1864.

Calvinistic Methodism claims to be the only Christian denomination in Wales to be of purely Welsh origin, and is rare among Presbyterian churches, by originating in the Methodist revival rather than deriving from the Calvinist Reformation. In 18th-century England, Calvinistic Methodism was represented by the followers of George Whitefield as opposed to those of John and Charles Wesley, although all the early Methodists in England and Wales worked together, regardless of Calvinist or Arminian (or Wesleyan) theology, for many years. With Calvinistic Methodists being absorbed into Presbyterianism, Methodism became defined by its adherence to Wesleyan-Arminian theology.

The movement's beginnings may be traced to the Rev. Griffith Jones (1684–1761), Church of England rector of Llanddowror, Carmarthenshire, whose sympathy for the poor led him to set on foot a system of circulating charity schools for the education of children. Griffith Jones's zeal, which contrasted strikingly with the general apathy of the clergy of the period, appealed to the public imagination, and his powerful preaching exercised a widespread influence. Many travelled long distances in order to attend his ministry. There was thus a considerable number of earnest people dispersed throughout the country waiting for the rousing of the parish clergy.

Griffith Jones, preaching at Llanddewi Brefi, Cardiganshire, found Daniel Rowland (1713–1790), curate of Llangeitho, in his audience, and his patronising attitude in listening drew from the preacher a personal supplication on his behalf in the middle of the discourse. Rowland was deeply moved, and became an ardent apostle of the new movement. Naturally a fine orator, his new-born zeal gave an edge to his eloquence and his fame spread abroad.

In May 1735, Howell Harris (1714–1773) underwent a religious conversion after listening to a sermon at Talgarth on the necessity of partaking of Holy Communion. This led to several weeks of self-examination and reached a climax at Communion on Whitsunday, May 1735. He immediately began to hold meetings in his own home, encouraging others to seek the same assurance that he had of Christ's forgiveness, and was soon invited to do the same at the houses of others. He became a fiery itinerant preacher, stirring to the depths every neighbourhood he visited. Harris' eldest brother sent him to Oxford in the autumn of 1735 where his friends hoped he "should be effectually cured of [his] 'enthusiasm', as they called it", but he left in the following February.