Guiñazú is a surname. Notable people with the surname include:
Enrique Ruiz Guiñazú (1884–1967), Argentine politician Eusebio Guiñazú (born 1982), Argentine rugby union player Luciano Guiñazú (born 1971), Argentine footballer Magdalena Ruiz Guiñazú (1931–2022), Argentine journalist Oseas Guiñazú, Argentine politician Pablo Guiñazú (born 1978), Argentine footballer