The First Church of Worcester, Mass., was organized in 1716. The first meetinghouse was erected in 1719, and the Rev. Andrew Gardner (1691-1773) was installed as the first minister. After 1854, it was more commonly referred to as the Old South Church, though never incorporated with that name. The church was incorporated as the First Church, Old South in 1908 and was called that until 1965 when it merged with the Tatnuck Congregational Church to form the First Congregational Church in Worcester.
Among its early pastors were Rev. Isaac Burr (1697-1751) and Rev. Thaddeus Maccarty (1721-1784). After the death of Rev. Maccarty in 1784, the church split due to the opposition of some church members to the election of Rev. Aaron Bancroft (1755-1839). The members who did not oppose the election of Bancroft formed the First Church, Second Parish of Worcester, Mass. (now known as the First Unitarian Church).
In 1790, Rev. Samuel Austin (1760-1830) was installed as pastor of the First Church. After his election as president of the University of Vermont in 1815, he remained pastor of the First Church in name only until 1818. Rev. Charles Augustus Goodrich (1790-1862) was called in 1815 to assist Rev. Austin and was installed as pastor in 1818. His election caused another split in the church in 1820. Rev. Goodrich was dismissed in 1820 and was succeeded by Rev. Aretius Hull (1788-1826). Rev. Rodney Augustus Miller (1798-1876) was installed in 1827. He asked for and was granted his dismissal in 1844 after greatly increasing church membership. Other pastors included Rev. George Phillips Smith (1814-1852), 1845-1852; Rev. Horace James (1818-1875), 1853-1863; and Rev. Royal B. Stratton (1826-1875), 1867-1872.