Table Mountain has an unusually rich biodiversity. Its vegetation consists predominantly of several different types of the unique and rich Cape Fynbos. The main vegetation type is endangered Peninsula Sandstone Fynbos, but critically endangered Peninsula Granite Fynbos, Peninsula Shale Renosterveld and Afromontane forest occur in smaller portions on the mountain.
The mountain's vegetation types form part of the Cape Floral Region protected areas. These protected areas are a World Heritage Site, and an estimated 2,200 species of plants are confined to Table Mountain - more than exist in the whole of the United Kingdom. Many of these species, including a great many types of proteas, are endemic to the mountain and can be found nowhere else. In addition, the Table Mountain range has the highest concentration of threatened species of any continental area of equivalent size in the world.
Remnant patches of indigenous forest persist in the wetter ravines. However, varieties of fynbos dominate on the more exposed parts of the mountain (such as above the city) where conditions are too dry and harsh for forests. The mountain's natural wildfire cycle seasonally burns and thus rejuvenates the fynbos vegetation on these exposed slopes.
The mountain has also suffered under a massive onslaught of invasive alien plants for well over a century, with perhaps the worst invader being the cluster pine. Considerable efforts have been made to control the rapid spread of these invasive alien plants.
The most common animal on the mountain is the dassie, or rock hyrax. They especially cluster around the upper cable station, near areas where tourists may discard or (illegally) supply food. There are also porcupines, mongooses, snakes and tortoises. The last lion in the area was shot circa 1802. Leopards persisted on the mountain until perhaps the 1920s but are now extinct locally. Two smaller, secretive, nocturnal carnivores, the rooikat (caracal) and the vaalboskat (also called the vaalkat or African Wild Cat) were once common on the mountain. The rooikat continues to be seen on rare occasions by mountaineers but the status of the vaalboskat is uncertain.
Himalayan tahrs, fugitive descendants of tahrs that escaped from Groote Schuur zoo in 1936, used to be common on the less accessible upper parts of the mountain. As an exotic species, they were almost eradicated through a culling programme initiated by the South African National Parks to make way for the reintroduction of indigenous klipspringers. Until recently there were also small numbers of fallow deer of European origin and sambar deer from southeast Asia. These were mainly in the Rhodes Memorial area but during the 1960s they could be found as far afield as Signal Hill. The animals may by now have been eliminated or relocated.