Gert Thys (born 12 November 1971 in Prieska, Northern Cape) is a male long-distance runner from South Africa, who represented his native country in the marathon at the 1996 and 2004 Summer Olympics.
Thys is a former African record holder in the marathon, and is the current holder of the South African record with his best of 2:06:33 from the 1999 Tokyo International Marathon, which was also the course record for that race.