| Province: | NB |
| Type: | NB |
| Route: | 170 |
| Maint: | New Brunswick Department of Transportation |
| Length Km: | 17.69 |
| Length Ref: | [1] |
| Length Round: | 1 |
| Established: | 1984 |
| Direction A: | East |
| Direction B: | West |
| Terminus A: | in Waweig |
| Cities: | St. Stephen |
| Terminus B: | in Calais, ME |
| Previous Type: | NB |
| Previous Route: | 165 |
| Next Type: | NB |
| Next Route: | 172 |
Route 170 is an 18km (11miles)-long east–west secondary highway in southwest New Brunswick, Canada.
The route's eastern terminus is at an intersection with Route 127 in Gilmans Corner, New Brunswick. From there, it runs west crossing the Waweig River to the small community of Simpson Corner, New Brunswick. Route 170 then crosses Oak Bay and runs until its terminus in St. Stephen.
Route 170 was commissioned in 1984 as a renumbering of the former Route 20, which had existed since 1965. Initially consisting only of Milltown Boulevard, it connected downtown St. Stephen with the smaller Milltown border crossing to the west. It was extended eastward along a former routing of Route 1 to Waweig in 2008.