Haynesville United Methodist Church (Haynesville, La.) is the product of multiple antecedent congregations and mergers. Haynesville Methodist Episcopal Church South began in the 1850s near the intersection of Louisiana Highway 534 and Triplet Road, approximately two miles south of downtown Haynesville. Around 1900, this church moved to the southwest intersection of Louisiana Highway 534 and Taylor Drive in downtown Haynesville.

Ward’s Chapel Methodist Episcopal Church South began around 1871 four miles north of Haynesville. In 1872, this congregation was renamed New Salem Methodist Episcopal Church South. Around 1921, the congregation merged with Haynesville Methodist Episcopal Church South.

Shady Grove Methodist Protestant Church was organized in 1853 about two miles west of Haynesville. In 1923, some members of this congregation organized a new church called Haynesville Methodist Protestant Church at the northwest intersection of Louisiana Highway 534 and Bridgeman Avenue in downtown Haynesville. In 1928, the remaining members from Shady Grove merged with the Haynesville congregation to become Shady Grove Methodist Protestant Church located in downtown Haynesville.

In 1939, Haynesville Methodist Church formed through the merger of Haynesville Methodist Episcopal Church South and Shady Grove Methodist Protestant Church. The merged congregation continued use of their two separate church buildings until selling the former Shady Grove Methodist Protestant Church building in 1957. In June 2022, Haynesville United Methodist Church disaffiliated from the United Methodist Church.