Eiulf Peter "Buster" Nupen (1 January 1902 – 29 January 1977) was a cricketer who played in 17 Test matches for South Africa between 1921–22 and 1935–36.
Constantly a deadly force against lesser batsmen on matting during the late 1920s – by which time his bowling on these wickets had been developed into a fine art – in 1930–31 Nupen was, owing to the absence of South Africa's former captain Nummy Deane due to poor form, chosen to captain the team. He did so with considerable skill and accomplished the best bowling of his Test career. He took 5 for 63 and 6 for 87 in the First Test to give South Africa victory by 28 runs, and 3 for 148 and 6 for 46 in the drawn Fourth Test. However, Nupen was thought so badly of on turf pitches that he was left out of the Third and Fifth Tests of that series – the first two ever played on turf in South Africa. Indeed, though he achieved his best-ever domestic figures the following year with 43 wickets for 434 runs (including 9 for 48 and 7 for 88 in the match against Griqualand West).