 Old St. Mary's is the oldest church in Cincinnati, and since 2017, home to The Cincinnati Oratory, a society of priests and brothers of The Congregation of the Oratory of St. Philip Neri.The church was organized in 1840 by German immigrants, at a time of dramatic growth in the city's population.Designed in the Greek Revival style by Franz Ignatz Erd, it is the second-oldest German-Catholic parish in the city and the oldest standing church in Cincinnati.