|Length:||6 miles (9.7 km)|
|Met:||B4362, B4357, B4366, A488|
|Now part of:||B4355|
|Route outline (key)|
The B4359 was a short rural B-road in eastern Radnorshire.
It started on the B4362 on the western edge of Presteigne town centre and headed north, soon crossing the River Lugg. After going through Norton the road climbed over the hills to reach the B4357 before descending into Knighton. It met the B4366 on the edge of the town centre before ending on the A488 a short distance further on.