St. Rose is situated in Southern Mercer County, in Marion Township. State Route 119 runs through the community. St. Rose is in the Marion Local school district.

A log church named St. Rosa Catholic Church was built in 1838. On June 29, 1854 a plat was recorded and named Rose Garden. The name of the Post Office was St. Rosa, which it eventually became known as.

St. Rose had an insurance company, mercantile business, general store, saloon and a stock farm. Many families made their living by farming.