Chandler van Steer from Matroosfontein was surprised to meet Van Niekerk on Wednesday.
The boy is also in a television advertisement.
Van Niekerk told Chandler: “Hi Chandler, I saw you in the advertisement. It was nice meeting you.” The youngster asked Van Niekerk: “What makes a good athlete?”
Van Niekerk responded: “Take part in all kinds of sporting codes before you finally decide.”
Chandler does athletics and plays cricket and rugby.
He said: “I always told them that I wanted to meet him. But I did not know that I was going to meet him today.”
His parents, Charlton and Yolanda van Steer, said they wanted to thank local radio station HeartFM that hosted the event.
Aden Thomas, a HeartFM presenter, said: “It is fantastic that Wayde took time to chat to Chandler. It was a quick chat, but he will always remember this day. This will inspire him to excel in sport.”