John Trevor Blokdyk (30 November 1935 in Krugersdorp, Transvaal – 19 March 1995 in Hekpoort, near Krugersdorp) was a South African motorcycle speedway rider and Formula One driver who participated in two World Championship Grands Prix, although qualifying for only one.
Blokdyk rode in speedway in Britain in the late 1950s and early 1960s for Poole Pirates and Ipswich Witches.
In 1962 he signed for Leicester Hunters but after one match for the team announced that he was quitting speedway to concentrate on motor racing.Blokdyk competed in Formula One for the first time in the non-Championship Rand Grand Prix at Kyalami in 1961, in a Cooper, but spun out early on.
He was more successful at his next race, the Natal Grand Prix at Westmead, where he finished 8th.
In late 1962, Blokdyk went to Europe to pursue a careera in Formula Junior and was soon a front-runner.
In 1963 he started his only World Championship race at East London, driving a Cooper-Maserati prepared by Scuderia Lupini, and coming in 12th.
He continued in Formula Junior in 1964 and then moved into Formula 3 and scored some good results, including a win at Magny-Cours and Nogaro.
He returned to South Africa for the 1964 Rand Grand Prix, where he retired his Cooper-Alfa Romeo with engine problems, and he failed to qualify for the 1965 South African Grand Prix.
Later in 1965 he raced in European Formula 3, and suffered serious injuries in a crash at Albi which ended his season.
On his return in 1966, he finished 6th at Rouen, and continued to race in Europe into the late 1960s, before returning to South Africa.
On his retirement he became a farmer, but died following a heart attack aged just 59.