First Presbyterian Church, also known as Old South, is a Presbyterian congregation in Newburyport, Massachusetts that is part of the Presbyterian Church (USA). The church building is located at 29 Federal Street in Newburyport. The self-declared mission of the church is to be “a biblically grounded Presbyterian Church seeking to be true to our rich historical heritage by providing a community of worship for all who wish to embrace a faith-centered life in the Christian tradition.” The current pastor is the Reverend Rob John.