# List of U.S. Highways in Idaho

The U.S. Highways in Idaho are the segments of the United States Numbered Highway System owned and maintained by the Idaho Transportation Department (ITD) in the U.S. state of Idaho.

## Mainline highways

| Number | Length (mi) | Length (km) | Southern or western terminus | Northern or eastern terminus | Formed | Removed | Notes |
| US 2 | 80.152 | 128.992 | US 2 / SH-41 in Oldtown | US 2 near Moyie Springs | 01926-01-011926 | current | |
| US 10 | 193.23 | 310.97 | US 10 in State Line | US 10 at Lookout Pass | 01926-01-011926 | 01977-01-011977 | Replaced by I-90 |
| US 12 | 174.210 | 280.364 | US 12 in Lewiston | US 12 at Lolo Pass | 01962-01-011962 | current | |
| US 20 | 406.300 | 653.876 | US 20 / US 26 near Parma | US 20 near West Yellowstone, MT | 01940-01-011940 | current | |
| US 26 | 402.500 | 647.761 | US 20 / US 26 near Parma | US 26 near Alpine, WY | 01952-01-011952 | current | |
| US 30 | 455.481 | 733.026 | US 30 near Fruitland | US 30 near Montpelier | 01926-01-011926 | current | |
| US 30N | — | — | — | — | — | — | |
| US 30N | — | — | — | — | — | — | |
| US 30S | — | — | — | — | — | — | |
| US 89 | 44.24 | 71.20 | US 89 near Fish Haven | US 89 near Geneva | 01939-01-011939 | current | |
| US 91 | 122.866 | 197.734 | US 91 near Preston | US 26 in Idaho Falls | 01926-01-011926 | current | |
| US 93 | 350.819 | 564.588 | US 93 near Jackpot, NV | US 93 at Lost Trail Pass | 01926-01-011926 | current | |
| US 95 | 538.562 | 866.732 | US 95 near Homedale | BC 95 near Eastport | 01926-01-011926 | current | |
| US 95E | — | — | — | — | — | — | |
| US 95W | — | — | — | — | — | — | |
| US 191 | — | — | US 191 near Malad City | US 191 at Targhee Pass | 01926-01-011926 | 01978-01-011978 | Replaced by I-15 |
| US 195 | 0.577 | 0.929 | US 95 near Lewiston | US 195 near Lewiston | 01979-01-011979 | current | |
| US 287 | — | — | US 287 at Raynolds Pass | US 287 at Targhee Pass | — | — | Replaced by SH-87 |
| US 410 | 3 | 4.8 | US 410 in Lewiston | US 95 in Lewiston | 01926-01-011926 | 01967-01-011967 | Replaced by US-12 |
| US 630 | — | — | US 630 near Weiser | US 95 in Weiser | 01928-01-011928 | 01931-01-011931 | Replaced by US-95 Spur |
| Former ||||||||

## Special routes

| Number | Length (mi) | Length (km) | Southern or western terminus | Northern or eastern terminus | Formed | Removed | Notes |
| US 10A | 62.648 | 100.822 | US 10A in Newport, WA | US 10A near Heron | 01941-01-011941 | 01967-01-011967 | Replaced with SH-200 and US-2 |
| US 10 Bus. | — | — | — | — | — | — | |
| US 20 Bus. | 3.640 | 5.858 | — | — | — | — | Serves Idaho Falls |
| US 20 Bus. | 1.684 | 2.710 | — | — | — | — | Serves Rigby |
| US 20 Bus. | 2.879 | 4.633 | — | — | — | — | Serves St. Anthony |
| US 20 Spur | — | — | — | — | — | — | Serves Boise |
| US 26 Bus. | 2.981 | 4.797 | — | — | — | — | Serves Ririe |
| US 30 Bus. | — | — | — | — | — | — | Serves Pocatello |
| US 30 Bus. | 10.270 | 16.528 | — | — | — | — | Serves Lava Hot Springs |
| US 91 Bus. | — | — | — | — | — | — | Serves McCammon |
| US 91 Bus. | — | — | — | — | — | — | Serves Inkom |
| US 93 Alt. | — | — | — | — | — | — | |
| US 93 Bus. | 8.110 | 13.052 | — | — | — | — | Serves Twin Falls |
| US 93 Spur | 0.91 | 1.46 | — | — | — | — | Serves Twin Falls |
| US 93 Spur | 0.391 | 0.629 | — | — | — | — | Serves Challis |
| US 95 Bus. | 1.420 | 2.285 | — | — | — | — | Serves Cottonwood |
| US 95 Bus. | 1.757 | 2.828 | — | — | — | — | Serves Craigmont |
| US 95 Bus. | 4.021 | 6.471 | — | — | — | — | Serves Winchester |
| US 95 Bus. | — | — | — | — | — | — | Serves Bonners Ferry |
| US 95 Spur | — | — | — | — | — | — | Serves Payette |
| US 95 Spur | 2.332 | 3.753 | — | — | — | — | Serves Weiser |
| US 95 Spur | 0.552 | 0.888 | — | — | — | — | Connects to US 195 |
| Former ||||||||