Liverpool Football Club congratulated Van Niekerk on Twitter, since the South African is one of the club's most famous fans.
You can also read how supporters responded, including proud South Africans and some Europeans who are hoping (jokingly?) that Van Niekerk should play on the Reds wing.
Some have asked whether he's faster than African stars Sadio Mane of Senegal and Mohamed Salah of Egypt? Of course he is! Van Niekerk is the fastest man on earth over 400m. Ever!
Here's what the South African told the media after picking up the gold medal.
“I’m just glad things worked out for us before the race; it is one thing believing you can get the gold medal and it is a different thing actually going out there and producing it,” Van Niekerk said.
“I know it was never going to be a walk in the park, as the competition is always going to be stiff - especially nowadays in the 400 metres. It is a day by day competition and anyone can come up with any result on the day so I am just so grateful that I can say I came through with the gold yet again.”
We behind you and proud of you — Nhlanhla Zungu (@NhlanhlaZungu6) August 10, 2017
Is he faster than Sadio and Mo? — Xer yecal (@PoeticRex) August 9, 2017
He should be the new reds' winger!!! Announce Van Niekerk to LFC!!! — Pablo (@Sportingpolesu) August 8, 2017