The 27-year-old also bagged the Test cricketer of the year while young opener Laura Wolvaardt took home the women's cricketer of the year and ODI cricketer of the year awards.
Pacer Lungi Ngidi was named ODI and T20 player of the year while David Miller was voted the fans' favourite player.
Anrich Nortje, who made his Test debut in India and took a five-for in the Test series against England, was adjudged the International men's 'newcomer' of the year.
Shabnim Ismail took home the women's T20 player of the year with left-arm spinner Nonkululeko Mlaba was recognised as the women's 'newcomer' of the Year.
This is the second time de Kock has won the men's Cricketer of the Year, having claimed the accolade in 2017.
With the win on Saturday night de Kock became one of the multiple winners of the award, joining the elite company of Jacques Kallis (2004 and 2011), Makhaya Ntini (2005 and 2006), Hashim Amla (2010 and 2013), AB de Villiers (2014 and 2015) and Kagiso Rabada (2016 and 2018).
The other previous winners since the awards were instituted in 2004 are Shaun Pollock (2007), Dale Steyn (2008), Graeme Smith (2009), Vernon Philander (2012) and Faf du Plessis (2019).
"Quinny is the leading wicketkeeper-batsman in Test cricket and is, in fact, one of the leading batsmen in both red ball and white-ball cricket. He is also starting to emerge as an outstanding leader," CSA Acting CEO, Jacques Faul was quoted as saying by ESPNcricinfo.
On the other hand, Wolvaardt became the youngest winner of South Africa's top women's award at 21 years and two months.
"At the age of 21 her best years are ahead of her and she will be a key player when the team go to the Women's World Cup next year," Faul said.
