Slovak mafia constitutes various organized crime groups in Slovakia, controlled primarily by Slovak interests. Slovak mafia does not have significant international presence and even in Slovakia, their activities are limited by boundaries set by the powerful Russian mafia (including Ukrainian and Chechen mafia) and various Balkan groups controlling much of the heroin trade. Slovak mafia is especially active in security business, construction and ownership of restaurants and nightclubs. According to the United States Department of Defense "both indigenous and foreign organized crime groups are well established in Slovakia". Under Slovak law, the creation or support of an organized crime group constitutes a crime.

In its modern form, the mafia is a young phenomenon in Slovakia, having truly emerged only after the end of communism in 1989. According to known Slovak sociologist Pavol Haulik from the MVK poll agency, "we can state that people imagine that the mafia has a very strong influence in Slovakia". In 2005 a list of mafia members suspected by the Slovak police leaked to the public, complete with lists of registered weapons and vehicles followed by two leaks of updated lists in 2011.