| State: | MO |
| Type: | MO |
| Route: | 231 |
| Established: | January 1964[1] |
| Length Mi: | 12.234 |
| Direction A: | South |
| Direction B: | North |
| Terminus A: | in Arnold |
| Terminus B: | River City Casino Boulevard in Lemay |
| Previous Type: | I |
| Next Type: | MO |
| Previous Route: | 229 |
| Next Route: | 240 |
| Counties: | Jefferson, St. Louis |
| Junction: | in Mehlville |
| Map Custom: | yes |
| Map Notes: | Route 231 highlighted in red |
Route 231 is a highway in the St. Louis, Missouri, area. It begins at U.S. Routes 61 and 67 (US 61 / US 67) in Arnold. It follows Telegraph Road through Jefferson and St. Louis counties, being Oakville's main thoroughfare. It then continues further north as Kingston Drive and then Broadway. It ends at River City Casino Boulevard, at the St. Louis city limits. The road continues north, further into St. Louis, as Broadway. It closely parallels the Mississippi River for its entire route.