Holy Trinity Catholic Church is a Catholic church located in Washington, D.C., in the United States. Located in the Georgetown neighborhood, it was established in 1787 and finished construction in 1794 and is the oldest Roman Catholic house of worship in both Georgetown and the larger city of Washington, D.C. The original building was vacated due to the lack of space and is now the Chapel of St. Ignatius, which is used as an auxiliary space for parish activities.