| State: | OH |
| Type: | US 1961 |
| Route: | 25 |
| Map Custom: | yes |
| Map Notes: | Former routing of US 25 prior to its decommissioning in Ohio denoted in red |
| Maint: | ODOT |
| Length Mi: | 208.18 |
| Established: | [1] |
| Decommissioned: | [2] |
| History: | Replaced by I-75 |
| Direction A: | South |
| Terminus A: | in Covington, KY |
| Junction: |
|
| Direction B: | North |
| Terminus B: | near Erie, Michigan |
| Counties: | Hamilton, Butler, Warren, Montgomery, Miami, Shelby, Auglaize, Allen, Hancock, Wood, Lucas |
| Previous Type: | OH 1920 |
| Previous Route: | 24 |
| Previous Dab: | 1923-1927 |
| Next Type: | OH |
| Next Route: | 25 |
US Highway 25 (US 25) was a part of the United States Numbered Highway System in the state of Ohio that ran from its present terminus near Covington, Kentucky, to its Michigan continuation. By the time it was decommissioned in 1973, all but the section north of Cygnet ran concurrently with Interstate 75 (I-75).
Before the U.S. Route system was established in 1926, the road that became US 25 was mostly numbered as State Route 6 (SR 6), but was numbered as SR 28 and SR 124 in the Cincinnati area. The route that became US 25 was also part of the eastern leg of the Dixie Highway. In 1950s and 1960s, US 25 was transferred to a new freeway that was the basis for I-75. Nearly all of the original road remains intact, however, still named Dixie Highway in some parts, and with some segments given county highway designations of CR-25A.
In 1973, the route was decommissioned in Ohio and Michigan due to its redundancy with Interstate highways. From Cygnet northward, the independent routing of US 25, up to its concurrency with US 24 at the intersection of Detroit Avenue and Cherry Street, became the whole of SR 25. The former concurrency to Telegraph Road retained the US 24 designation, while the remaining segment of Detroit Avenue northward to the state line was decommissioned as a state highway, continuing into Michigan as M-125/Dixie Highway. In 1986, the segment of SR 25 along Detroit Avenue was swapped with US 24, with the state route taking a new alignment from downtown Toledo to I-280.