|Location Map ( geo)|
|Distance:||0.7 miles (1.1 km)|
|Met (1923):||B663, B665|
|Now part of:||B663|
|Route outline (key)|
The B666 was a short link road on the edge of the Northamptonshire town of Raunds. Starting on the B663 High Street in the town centre the road headed west along Brick Kiln Road, ending after less than a mile on the B665, the road to Thrapston.
Owing to the short length of the road it is not known how long it lasted. The road is now a spur of the B663 and it seems likely that this renumbering happened sooner rather than later; it certainly had by the 1950s.