The R103 is a Regional Route in South Africa that is the designation for some of the old sections of roads that were previously the N3, prior to upgrading.

The R103 begins as the Old Main Road and leaves Hillcrest in a roughly north-west direction and enters Cato Ridge from the east.

In Cato Ridge, the road crosses the N3 at the 53 exit and then follows the south side of the N3, leaving the eThekwini Metropolitan Municipality, before recrossing the N3 freeway at Camperdown.

Soon after, the R56 breaks off to the east and the R103 leaves Scottsville, crossing the Msunduzi River and heading north-west into the Pietermaritzburg CBD as its main road (Chief Albert Luthuli Street).

The road resumes following the N3 in a north-westerly direction, passing through Hilton before reaching the outskirts of Howick, where it meets the north-eastern terminus of the R617.

In Villiers, the R103 reaches an intersection with the R26 and the N3, just north of the N3's Wilge Toll Plaza and just south of the N3's Vaal River crossing.

The R103 reaches a t-junction in Roodekop, south of Wadeville, Germiston, where it becomes part of the Nederveen Highway and is cosigned with the R554 westwards towards Alberton.