John Danaher may refer to: John Danaher (VC) (1860–1919), Irish recipient of the Victoria Cross John A. Danaher (1899–1990), U.S. senator and judge from Connecticut John A. Danaher III (born 1950), grandson of the above, commissioner of the Connecticut Department of Public Safety John Danaher (martial artist) (born 1967), Brazilian jiu-jitsu and mixed martial arts instructor John Danaher (ethicist), Irish legal scholar and philosopher