The N12 is a national route in South Africa which runs from George through Beaufort West, Kimberley, Klerksdorp and Johannesburg to eMalahleni.

The road runs roughly from south to north, however, once it passes Kimberley in the Northern Cape, it gradually turns eastward.

The N1 and N12 routes remain as one road for the next 75 km north-east from Beaufort West to Three Sisters, where they enter the Northern Cape.

[1] The N12 continues north-north-east for 254 km, through Strydenburg and Hopetown (where it crosses the Orange River), to Kimberley (capital city of the Northern Cape).

It makes a 100 km journey north-east, following the Vaal River, through Christiana, to Bloemhof, where it meets the R34 road (co-signed for 2 kilometres) and passes through as Prince Street.

[1] From Bloemhof, the N12 continues north-east for 150 km, passed Wolmaransstad, to Klerksdorp, where it becomes a freeway (dual carriageway highway) and meets the R30 road.

The N12 proceeds eastwards to meet the N1 national route again (north eastbound only) at the Misgund Interchange adjacent to the Olifantsvlei Nature Reserve.

[1] The N12 joins the N1 and they become one freeway northwards for four kilometres, meeting the R553 Golden Highway, up to the Diepkloof Interchange, the south-western corner of the Johannesburg Ring Road.

The N12 highway continues eastwards, through many suburbs of Johannesburg South (including Ridgeway, Winchester Hills and Oakdene), to Alberton.

At the Reading interchange with the R59 Sybrand van Niekerk Freeway in Alberton, the N12 begins to change direction, slowly turning northwards.

At this interchange, the N12 leaves the Eastern Bypass portion of the Johannesburg Ring Road (which remains designated as the N3 northwards) and joins the R24 Airport Freeway eastwards.

[1] It continues eastwards, bypassing Daveyton (where it meets the R51) and Etwatwa, to leave the City of Ekurhuleni Metropolitan Municipality and enter the Mpumalanga Province.

From the R50 Delmas exit, the N12 goes for another 60 km east, meeting the R42 and bypassing Ogies, to enter eMalahleni (Witbank), where it passes through the southern suburbs.

The N12 between Three Sisters and Warrenton is very important as it is part of the Trans-African Highway Network number 4 Extension between Gaborone and Cape Town.