Daniel John Patrick "Danny" Greene (November 14, 1933 – October 6, 1977) was an Irish American mobster and associate of Cleveland mobster John Nardi during the gang war for the city's criminal operations during the 1970s. Competing gangsters set off more than 35 bombs, most attached to cars in murder attempts, many successful. Greene had gained power first in a local chapter of the International Longshoremen's Association, where he was elected president in the early 1960s. Greene pushed into Cleveland rackets and began competing with the Sicilian Mafia for control of the city. He set up his own group called the Celtic Club, complete with enforcers.