Kinyanjui is a surname of Kenyan origin. Notable people with the surname include:
Arthur Kinyanjui Magugu (1934–2012), Kenyan politician Kui Kinyanjui, Kenyan reporter Lee Kinyanjui (born 1972), Kenyan politician Nephat Kinyanjui (born 1977), Kenyan long-distance runner Kinyanjui Kombani (born 1981), Kenyan author