The following list is especially useful if you’re looking for specific information about local National Parks and Game Reserves in Eastern and Southern Africa. Also a great source of info before planning your African safari. Enjoy! 
NB: Click on the images to be redirected to the appropriate websites!
East Africa National Parks Websites
Uganda Wildlife Authority
UWA’s mission is to conserve, economically develop and sustainably manage the wildlife and Protected Areas of Uganda in partnership with neighbouring communities and other stakeholders for the benefit of the people of Uganda and the global community.
Kenya Wildlife Service
The Kenya Wildlife Service (KWS) conserves and manages Kenya’s wildlife for the Kenyan people and the world. It is a state corporation established by an Act of Parliament Cap 376 with the mandate to conserve and manage wildlife in Kenya, and to enforce related laws and regulations.
Tanzania National Parks
The Official Website!
Southern Africa National Parks Websites
The Zambia Tourism Board
Especially of interest are the Places to Visit, Game Reserves, Safaris, Wildlife and Birdlife sections.
Malawi Tourism
Check out their Parks & Reserves section.
Mozambique
“Areas de Conservaçao Transfronteira”. Most of the website is in Portuguese though! 
For English speakers, you can try Visit Mozambique.
Zimbabwe Parks and Wildlife Management Authority
Very user-friendly website: be sure to have a look at their Hot Destinations!
Botswana Tourism Board
Come and explore the diverse cultures of its people and nature at its best. If there’s a place where one wishes time could stand still, it is the beautiful country you will be viewing on this Website.
Namibia Tourism Board
The Parks & Game and Flora & Fauna sections are most relevant in this case.
South African National Parks
South African National Parks (SANParks) manages a system of parks which represents the indigenous fauna, flora, landscapes and associated cultural heritage of the country. Of all the national parks, most have overnight tourist facilities, with an unrivalled variety of accommodation in arid, coastal, mountain and bushveld habitats.
Besides providing incredibly valuable information on all South African national parks, the website also has quite a few sections worth visiting like the Webcams at SANParks, and the stunning Public Sightings Galleries.
Other Useful Links
Namibia Wildlife Resorts (NWR).
Tags: national parks websites
