The B58 is a relatively short B-road in east Antrim.
The road's northern end, in Ballynure, has changed a couple of times. Originally the B58 started on the A8 in the centre of Ballynure and then headed east along Carrickfergus Road. It was later rerouted along a formerly unclassified road to bypass Ballynure to the south, so ending at a roundabout where it also met the A57. Then in 2015 Ballynure was bypassed by the A8 and the B58 took over the old road through town. Our road therefore starts at a GSJ at the northern end of the A8 bypass and heads southwest through town, passing its original northern end, to the roundabout mentioned above, which now forms part of the GSJ at the other end of the bypass. Here it bears sharply left to head east, picking up its original route on the southern edge of town where priorities now favour the new road.
The B58 continues eastwards. It climbs to begin with and is then relatively flat for a few miles before climbing again. On meeting the B99 the B58 TOTSOs right to head south along a straight road through a wood. Now descending, it passes the North Woodburn Reservoir (which is hidden behind an earth bank) before reaching open fields once again. The road continues to descend, with Belfast Lough (an inlet of the sea) visible ahead.
A mile or so later on the road goes into cutting, with the old line of the road to the right. The next road to the left is then the original B58 but this had to be bypassed due to subsidence so the road now continues ahead to a T-junction on the B90. After a short multiplex to the left the B58 takes the next turn to the right; the original line of the road crossed the B90 at an ordinary crossroads.
The B58 then heads south along Prospect Road into Carrickfergus. To begin with the road remains semi-rural but it soon bends to the right to cross the Belfast to Larne railway line by Clipperstown station; this marks the beginning of the town proper. The B58 runs along Ellis Street and Davys Street to end at a T-junction on the A2, just inland from the old quay.