Abe Jonker was a South African cyclist who was active in the late 1950s and early 1960s. In 1956 Jonker was selected to compete on both the road and track at the Melbourne Olympics. Although he did not finish in the road race, he just missed out on a medal on the track, finishing fourth in the 4,000 metres team pursuit. The South African quartet lost to France in the semi-finals, before beating narrowly beaten by Great Britain in the bronze medal race. Jonker returned to the Olympics four years later for the 1960 Games in Roma, once again riding in the 4,000 metres team pursuit. This time the South African team were well beaten in their heat by the Netherlands and were eliminated.