Cantacuzino (Romanian pronunciation: ['jo?an kantakuzi'no], also Ion Cantacuzino; 25 November 1863 – 14 January 1934) was a renowned Romanian physician and bacteriologist, a professor at the Romanian School of Medicine and Pharmacy and a member of the Romanian Academy.
He established the fields of microbiology and experimental medicine in Romania, and founded the Ioan Cantacuzino Institute.