The First Church of Christ, Unitarian, also known as First Church in Lancaster and colloquially as "the Bulfinch Meetinghouse", is a historic congregation with its meeting house located at 725 Main Street facing the Common in Lancaster, Massachusetts. The church's fifth meeting house, built in 1816, was designed by architect Charles Bulfinch, and was designated a National Historic Landmark in 1977, recognizing it as one of Bulfinch's finest works.