Yakuza (Japanese: ヤクザ, IPA: [jaꜜkɯza]) , also known as gokudō (極道, "the extreme path", IPA: [gokɯꜜdoː]), are members of transnational organized crime syndicates originating in Japan. The Japanese police and media, by request of the police, call them bōryokudan (暴力団, "violent groups", IPA: [boːɾʲokɯꜜdaɴ]), while the yakuza call themselves ninkyō dantai (任侠団体, "chivalrous organizations", IPA: [ɲiŋkʲoː dantai]). The English equivalent for the term yakuza is gangster, meaning an individual involved in a Mafia-like criminal organization. The yakuza are known for their strict codes of conduct, their organized fiefdom nature and several unconventional ritual practices such as yubitsume or amputation of the left little finger. Members are often portrayed as males with heavily-tattooed bodies and wearing fundoshi, sometimes with a kimono or, in more recent years, a Western-style "sharp" suit covering them. This group is still regarded as being among "the most sophisticated and wealthiest criminal organizations".

At their height, the yakuza maintained a large presence in the Japanese media and they also operated internationally. In 1963, the number of Yakuza members and quasi-members reached a peak of 184,100. However, this number has drastically dropped, a decline attributed to changing market opportunities and several legal and social developments in Japan which discourage the growth of yakuza membership. In 1991 it had 63,800 members and 27,200 quasi-members, but by 2022 it will have only 11,400 members and 11,000 quasi-members. The yakuza are aging because young people do not easily join, and their average age at the end of 2022 is 54.2 years: 5.4% are in their 20s, 12.9% in their 30s, 26.3% in their 40s, 30.8% in their 50s, 12.5% in their 60s, and 11.6% in their 70s or older, with more than half of the members in their 50s or older.

The yakuza still regularly engage in an array of criminal activities and many Japanese citizens still remain fearful of the threat these individuals pose to their safety. There remains no strict prohibition on yakuza membership in Japan today, although many pieces of legislation has been passed by the Japanese government aimed at impeding revenue and increasing liability for criminal activities.