Dr Zachary Onyonka (1939–1996) was a Kenyan prominent politician and the first Kisii man to earn a PhD.
He first came into the public limelight in 1969 when he vied for Kitutu West parliamentary seat and dislodged incumbent Lawrence Sagini Ndemo, the first Cabinet minister from the Gusii region. After being elected, he was appointed to the Cabinet by President Daniel Moi and served in several portfolios, including Foreign Affairs, Economic Planning and Development, Education and Trade. Others were Information and Broadcasting, Health, and Research, Science and Technology.