Du Plessis was born 21 October 1949 in Vereeniging, several sources incorrectly identify Krugersdorp as Du Plessis' town of birth, including the International Rugby Hall of Fame and ESPN Scrum. But in an interview Du Plessis pointed to Vereeniging as his place of birth, and this is confirmed in his profile on the Springboks' official site, and on the South African government's national orders. into a sporting family. His mother, Pat (née Smethurst) captained South Africa's women's national hockey side in 1954. A maternal uncle, Horace, was captain of the national soccer team that toured Australia and New Zealand in 1947.