The R503 is a Regional Route in South Africa. It begins from the N18 in the village of Pudimoe, North West, and runs west-east. The first town it passes through is Amalia. It then reaches Schweizer-Reneke, where it intersects with the R506 / R34. The next town it passes through is Wolmaransstad, where it crosses the N12 and is briefly co-signed with it. Heading onward to Leeudoringstad, where it meets the R502 at a staggered junction. Crossing the Vaal it enters the Free State where it ends in Bothaville at a four-way intersection with the R30. The west-east road continues as the R59.