The name "De Aar" means "the vein" or "the artery" and refers to an underground watercourse. It became a municipality in 1904. It was originally called Brounger Junction.
De Aar is the second biggest railway junction in South Africa behind Germiston.
Although the surrounding area is quite arid there is a lot of sheep farming for both meat and wool. In face De Aar has the biggest abattoir in the Southern Hemisphere.
Anti-war campaigner Olive Schreiner lived in De Aar between 1907 and 1913. The house that she stayed in is a restaurant nowadays.
The De Aar area is popular amongst Hang-gliding and Paragliding pilots and various records have been set here.
There are 3 nature reserves in the area - Rolfontein Nature Reserve, Karoo Gariep Conservancy and Doornkloof Nature Reserve.
Bushman rock art can be seen at Danfontein, Nooitgadeacht and Brandfontein.
There is a Garden of Rememberance with the graves of British soldiers killed during the Anglo-Boer war.