Ciacci is a surname of Italian origin. Notable people with the surname include:
Little Tony (Antonio Ciacci; 1941–2013), Sammarinese pop singer and actor Catullo Ciacci (1934–1996), Italian cyclist Matteo Ciacci (born 1990), Sammarinese politician Nicola Ciacci (born 1982), Sammarinese footballer Sante Ciacci (born 1941), Sammarinese cyclist