St. Croix is an unincorporated community in northern Oil Township, Perry County, in the U.S. state of Indiana.
The community lies along on the western edge of the Hoosier National Forest, near the intersection of State Road 62, Interstate 64, and State Road 37, northeast of the city of Tell City, the county seat of Perry County. Its elevation is 725 feet (221 m), and it is located at 38°13′26″N 86°35′11″W / 38.22389°N 86.58639°W / 38.22389; -86.58639 (38.2239489, -86.5863736). Main points of interest in St. Croix include Holy Cross Church, cemetery, and Church Hall as well as the Etienne Saw Mill and Bear Hollow Mulch. Although St. Croix is unincorporated, it had a post office, with the ZIP code of 47576.