Starting 02nd July 2015, you will need to apply for an e-visa online to enter Kenya. You can also apply for a transit Kenya visa or a combined East Africa Visa.
Please note, apply for the East Africa Visa only if your port of entry to the East African countries (Kenya, Rwanda and Uganda) in Kenya.
Click here, for all the details.
Effective 01 September 2015, you will be denied boarding your flight to Kenya or denied entry to Kenya if you do not have your printed copy of your Kenya e-visa with you.
Download the announcement from Kenya Airways, Download.