Arthur Nicholas "Sas" de Kock (11 January 1866 – 6 July 1957) was a South African international rugby union winger. Born in Hopetown, he attended Paul Roos Gymnasium before playing provincial rugby for Griqualand West. He made his only appearance for South Africa during Great Britain's 1891 tour, South Africa's first as a Test nation. He was selected to play in the 2nd match of the three Test series, Great Britain won the game 3–0. de Kock died in 1957, in Springs, at the age of 91.