The B6455 was a link road to the south of Dalkeith. It was originally unclassified but gained its number in the mid-1930s. In the 1970s the eastern section of the road was bypassed by the B6482 and that number quickly took over the rest of the route, with the bypassed section declassified.
Starting on the A7 by the railway viaduct west of Newtongrange the B6455 headed eastwards to cross the B703 before zigzagging into Easthouses. It continued north and soon ended on the A68 to the east of Dalkeith town centre.