In 1696 the residents of the town of Watertown, Massachusetts, voted to support two meeting houses. The First Church, which was established in 1630, became the church in the East Precinct. A new church, the West Precinct Church, was established in 1696 to serve the western section of the town, which was largely a farming community. The first physical structure to hold the parish was built in 1696. By 1722 the first church building had become unsuitable for the congregation; that year a disused building from Newton was purchased, disassembled, and reassembled in Waltham to become the first meeting house. In 1738 the town of Waltham was incorporated from the West Precinct of Watertown and the West Precinct Church became the First Parish in Waltham. By 1767 the congregation had once again outgrown the meeting house and before the end of 1768 the second meeting house was constructed and in use.
By 1813 the First Parish in Waltham was either fully Unitarian or heavily moving towards Unitarianism. The Second Religious Society in Waltham formed in 1813, likely in response to the ecclesiastical direction of the First Parish. In 1820 this society split again with one half forming the First Congregational Church, also known as the Third Trinitarian Society, and the other half retained the name, Second Religious Society, but adopted Unitarianism. In 1838 the Second Congregational Society merged with the First Parish to become the only Unitarian congregation in Waltham. At that time the newly merged congregation built the third meeting house.
In 1933 the third meeting house was destroyed by a fire. The fourth meeting house, designed by Allen & Collens from Boston, was built on the foundation of the third meeting house. The fourth meeting house, a Classic Revival structure, was listed on the National Register of Historic Places in 1989. In 1958 the First Parish merged with the First Universalist Society of Waltham to become the First Parish Church in Waltham, Universalist-Unitarian. This church continues to serve the local community today.