John Danaher is a Brazilian jiu-jitsu (BJJ) black belt under Renzo Gracie and an instructor at the Renzo Gracie Academy in New York City, being widely regarded by within the grappling community as one of the best coaches of his generation.

Praised by some of the prime figures in combat sports such as Mixed martial art (MMA) guru Greg Jackson (MMA trainer) for his knowledge and teaching capabilities, Danaher is best known for his work with athletes such as Georges st.

pierre ^[1], Garry Tonon (BJJ), Gordon Ryan, and Eddie Cummings (Whom has since left the team) ^[0], known among BJJ fans as the Danaher Death Squad (DDS) .