The steep climatic north-south gradient comprises a multitude of habitats containing a remarkable diversity of life, making it the most biodiverse savanna in the world, and ranges from the dry Sudanian zone to the comparatively humid Guinea Savanna. These habitats include for the most part different savannas, forest islands, gallery forests and riparian grasslands, thereby providing an ideal example of transitional habitats throughout various climatic zones. The Comoé river, flowing throughout Côte d'Ivoire also allowed for various habitats and plant associations normally found further south to exist in the park, like patches of dense gallery forest in the vicinity of the river. This variety of habitats throughout different zones and the vast area dedicated to the conservation of natural resources make it an ecological unit of particular importance and a UNESCO World heritage site
Geomorphologically the park consists of large plains through which the Comoé River and its tributaries flow (Iringou, Bavé, Kongo). The Comoé river and its tributaries form the main drainage and the Comoé runs through the park for 230 kilometres (140 mi), with watercourses also draining to the Volta in the east. There are also various permanent and semi permanent ponds distributed throughout the park, most of which dry out during the dry season. The soils are for the most part infertile and unsuitable for cultivation. Granite inselbergs also rise up to 600 metres (2,000 ft) within the park's area.
Comoé National Park has the most biodiverse savannah in the world and forms the northern limit for many animal species, like the yellow-backed duiker and bongo. There are a total of 135 mammal species in the park. This includes 11 species of primates like the olive baboon, green monkey, diana monkey, lesser spot-nosed monkey, Mona monkey, black and white colobus, white collared mangabey and chimpanzee. A total of 17 carnivore species are present, like the lion, leopard, giant pangolin, rock hyrax, spotted hyena and aardvark. There are also 21 species of artiodactyl present in the park including hippopotamus, bushpig, sitatunga, warthog, buffalo, kob, red-flanked duiker, bushbuck, waterbuck, roan antelope and oribi. Threatened mammal species include the African elephant, wild dogs and possibly one of the last large populations of chimpanzee left in the Ivory Coast.
There are over 500 species of birds, of which roughly 20% are inter-African migratory birds and another 5% palearctic migratory birds. Some prominent bird species include the Denham's bustard, yellow-casqued hornbill, brown-cheeked hornbill, hammerkop, black-winged stilt, various raptors, four of the six West African stork species and five vulture species. The park also contains 36 out of the 38 of the iconic bird species found in Sudo-Guinean savannas.
The Comoé river and its tributaries contain at least 60 different species of fish and allow for an unusually high diversity of amphibian species for a savannah habitat with 35 described species. There are also a total of 71 described reptile species, of which three are crocodiles: the dwarf crocodile (threatened), Nile crocodile and slender-snouted crocodile. The floodplains around the river create seasonal grasslands that are optimal feeding grounds for hippopotamus and migratory birds.
The property contains around 620 plant species, composed of 191 ligneous species (62 trees, 129 shrubs and vines) and 429 herbaceous species, including 104 grasses. The park encompasses various transitional habitat, from forest to savannah, with various plant associations typical of more southern regions. Gallery forests, open forests and riparian grasslands occur alongside all types of savannah, which occupy roughly 90% of the park. The forest is composed of many leguminous trees. In the gallery forests Cynometra sp. is the most dominant genus while patches of dry forest islands are generally inhabited by Anogeissus leiocarpus, Antiaris africana, Isoberlinia doka, Cola cordifolia, the nationally threatened Chlorophora excelsa and Blighia unijugata. In the flood plains Hyparrhenia rufa is the most common species.