St. Paul is a city in Marion County, Oregon, United States.The population was 421 at the 2010 census.
French Prairie settlers built a log church near this locale in 1836.On January 6, 1839, Father (later Archbishop) Blanchet celebrated the first Catholic mass in Oregon at St. Paul, when he blessed the log church and dedicated it to St. Paul.St. Paul Roman Catholic Church was built in 1846 and is the oldest brick building in the Pacific Northwest.St. Paul post office was established in 1874. The city was incorporated in 1901.According to the United States Census Bureau, the city has a total area of 0.29 square miles (0.75 km2), all of it land.The city is near Mission Creek, a tributary of Champoeg Creek, which flows into the Willamette River.