Kentrosaurus aethiopicus was a relatively small stegosaurian dinosaur. It was about 4.5 m (15 ft.) long, and is estimated to have weighed about 2 t (2.2 tn.). It was a herbivore.

German scientists discovered the dinosaur in the early 1900s, in the Tendagaru fossil beds in what is now Tanzania.

The dinosaur's lower back and thick, strong tail were covered by large, almost upright, bony growths that ran in pairs in a line. These growths most likely served a defensive function. The tail sported two pairs of sharp, 60 cm-long (2 ft.) spikes that were probably used for lashing out against predators.

It is from these tail spikes that Kentrosaurus derived its name when it was described in 1915. Kentrosaurus essentially means "sharp-pointed lizard" or "spiked lizard", and aethiopicus refers to the fact that it was found in southern Africa. There is only the one species known for this genus.

Blood circulating through the upright bony plates along the upper body and neck helped to cool or warm the animal.

Kentrosaurus lived during the Late Jurassic Period, about 155 to 140 million years ago. It is related to the larger, well-known Stegosaurus of North America.