Free Church of Tonga, Methodist church in Nuku'alofa, Tonga.

The Free Church of Tonga (Siasi ʻo Tonga Tauʻatāina) is a Methodist denomination in the Kingdom of Tonga, not a single building; its administration centre stands at the edge of Tonga's central business district in Nuku'alofa. It was founded in January 1885 at Lifuka, Ha'apai, by King George Tupou I on the advice of Shirley Baker, and renamed the Church of Free Tonga by George Tupou II in 1898.

The church was established in 1885 when it separated from the Methodist Church of Australia to become an independent religious institution. This separation allowed the congregation to develop its own direction and maintain local control over spiritual matters.

The name Siasi ʻo Tonga Tauʻatāina means "Free Church of Tonga", adopted in 1885 to signal independence from the Australian Wesleyan Methodist Church. Queen Sālote Tupou III and her son Taufaʻahau Tupou IV were both christened in the Free Church, tying the denomination to the Tongan royal establishment. The breakaway group led by Jabez B. Watkin kept the name after the 1924 reunion, so today it denotes the continuing church rather than the united Free Wesleyan Church.

The church's administration centre sits on the outskirts of Nuku'alofa's central business district, so it is reached from the town centre rather than from a residential parish. Its districts and congregations extend beyond Tonga to New Zealand, Australia, the USA, Fiji and American Samoa. About 20% of church funds go to education, supporting three Tailulu Colleges on Tongatapu, Haʻapai and Vavaʻu.

The church runs three high schools, all named Tailulu College, one each on Tongatapu, Haʻapai and Vavaʻu, founded under Rev. Sione Fonua. It also runs two preschools in Auckland, New Zealand, Falemasiva and Lou'olive, and spends about 20% of its funds on education.