| State: | ND |
| Type: | ND |
| Route: | 66 |
| Length Mi: | 138.720 |
| Length Round: | 3 |
| Map Custom: | yes |
| Established: | c. 1963 |
| Direction A: | West |
| Terminus A: | south of Dunseith |
| Junction: | |
| Direction B: | East |
| Terminus B: | at the Minnesota/ North Dakota border |
| Counties: | Cavalier, Pembina, Rolette, Towner |
| Previous Type: | ND |
| Previous Route: | 65 |
| Next Type: | ND |
| Next Route: | 67 |
North Dakota Highway 66 (ND 66) is a 138.72adj=midNaNadj=mid east–west state highway in the U.S. state of North Dakota. ND 66's western terminus is at ND 3 south of Dunseith, and the eastern terminus is a continuation as Minnesota State Highway 11 (MN 11) at the Minnesota/ North Dakota border.[1]