Saint Louis is an unincorporated community in the French Prairie area of Marion County, Oregon, United States, about three miles northwest of Gervais, at the intersection of St. Louis and Manning roads.

It is part of the Salem Metropolitan Statistical Area.

One of the oldest communities in the state, Saint Louis was founded in 1845 when a Jesuit missionary, Reverend Aloysius Verecuysee, built a log church there for the early settlers.

[4] The current Saint Louis cemetery is northwest of the church.

[7] Saint Louis post office operated from 1860 until 1901; today Saint Louis has a Gervais mailing address.