Designed by Babin, a Beaumont architect, St. James is yet another indication of how high architectural standards were in Port Arthur for much of the twentieth century. The church is an octagon in plan, faced with a pedimented entrance pavilion and austere, unframed, arched windows. Classical detail is executed in cast stone. A square tower rises to one side of the church. Its cupola-topped summit is echoed in the detailing of the lantern at the apex of the church's conical copper roof.