| State: | UT |
| Type: | SR |
| Route: | 231 |
| Alternate Name: | State Street |
| Map Custom: | yes |
| Section: | 129 |
| Length Mi: | 0.085 |
| Length Round: | 3 |
| Length Ref: | [1] |
| Established: | 2018 |
| Direction A: | South |
| Terminus A: | in Fairview |
| Direction B: | North |
| Terminus B: | in Fairview |
| Counties: | Sanpete |
| Previous Type: | SR |
| Previous Route: | 228 |
| Next Type: | SR |
| Next Route: | 232 |
State Route 231 (SR-231) is the shortest state highway in the U.S. state of Utah. It serves as a connection between U.S. Route 89 (US-89) and SR-31 in Fairview.
SR-231 begins at the intersection of State Street (US-89) and Milburn Road, proceeding north on the latter. After slightly less than a city block, the route comes to its northern terminus at Canyon Road (SR-31). The road continues to the north towards Milburn, but it is not state-maintained beyond the SR-31 junction. The entire length of SR-231 is 0.085miles.[1]
The road from Fairview north to Milburn was added to the state route system in 1912 as part of SR-32,[2] and in 1926 it became part of the original alignment of US-89.[3] US-89 was moved to bypass Milburn in 1937, and the old route between Fairview and Milburn was transferred to SR-91. The routes remained in this configuration until 1969, when SR-91 was removed from the state highway system in a mass deletion of minor state highways and transferred to local jurisdiction.
However, the short segment of former SR-91 between US-89 and SR-31 in Fairview continued to be used as the primary connection from northbound US-89 to eastbound SR-31, and vice versa. As a result, in the meeting of the Utah Transportation Commission on October 12, 2018, this one-block segment was re-added to the state highway system as SR-231.[4]