The B7021 is a rural road on Wigtownshire's Machars Peninsula. It was originally unclassified but had gained its number by 1932.
The road starts on the A746 at the northern end of Whithorn, just beyond the fork between that road and the B7004. It quickly leaves the town behind and heads west, striding out across fields peppered with scattered farms. The landscape is one of gently rolling hills, the road being a series of short straights and sweeping bends as it undulates westwards. After about five miles, it dips down through some woodland; just beyond, a lone standing stone is visible on the horizon. Less than half a mile further on, the B7021 comes to an end at a sharp bend on the B7085.