The Siderno Group is a criminal association in Canada, Australia and Italy related to the 'Ndrangheta, a Mafia-type organization in Calabria. The association is labelled the "Siderno Group" because its members primarily came from the town of Siderno on the Ionian coast in Calabria and migrated to Canada and Australia in the 1950s.

The Siderno crime group operates throughout Canada, the United States, Australia and Europe and is composed of a group of families who are related by blood or marriage. Siderno is home to one of the 'Ndrangheta's biggest and most important clans, the Commisso 'ndrina, involved in the global cocaine business and money laundering. According to the Siderno police force, "The criminal minds of Siderno are in Canada."

The group has moved narcotics over three continents. They had contacts in Bolivia, Venezuela, Brazil, Chile and Peru, and had permanent representation in Colombia for drugs and in Costa Rica and Panama for money laundering. Its key man in Colombia, Roberto Pannunzi, was arrested in Medellín, Colombia in 1994. In the past, he had been in charge of heroin shipments from Turkey through Italy to the United States.

In Canada, in particular in the Greater Toronto Area, a branch of the Siderno Group has been active since the 1950s. Until 1980, the head of the Group was Michele (Mike) Racco. He maintained close contacts with the Luppino crime family in Hamilton, Ontario and with the Cotroni crime family in Montreal. By 1962, Racco established a crimini and Camera di Controllo in Canada with the help of Giacomo Luppino and Rocco Zito. Salvatore Triumbari and Filippo Vendemini were also co-founders until Racco sanctioned their murders in 1967 and 1969 respectively, due to disputes. Racco had been urged to start the Canadian operation by Antonio Macrì, the undisputed boss of Siderno until he was killed in January 1975. Michele Racco died of cancer in January 1980.

A May 2018 news report explained the group's initial involvement in Canada. "Siderno's Old World 'Ndrangheta boss sent acolytes to populate the New World" including Michele Racco who settled in Toronto in 1952, followed by other mob families. According to investigators in Italy, by 2010, Toronto's 'Ndrangheta had climbed "to the top of the criminal world" with "an unbreakable umbilical cord" to Calabria. The report stated that there were seven senior 'Ndrangheta bosses in the Greater Toronto Area, some on the Camera di Controllo, the "board of directors".

The Toronto-area Siderno group has included the Coluccio, Tavernese, DeMaria, Figliomeni, Ruso, and Commisso crime families; Leaders are based both in Calabria and Ontario. Carmine Verduci and Cosimo Stalteri were also linked with the 'Ndrangheta group.

By 1976, Cosimo Commisso was considered by the police to be a capo bastone (underboss) in the Siderno group. By the early 1980s, Zito was boss of the Toronto Siderno Group after the death of Michele Racco. Racco's son Domenic Racco also filled his void briefly. In January 1983, Anthony Musitano of the Hamilton-based Musitano crime family was sentenced to 15 years in prison for bombing a number of businesses in Hamilton, including bakeries. While in prison, he orchestrated the murder of Domenic Racco, who violated their cocaine trade agreement by dealing behind Musitano's back, and also owed the Musitano family as much as $500,000. Racco was also arrested in February 1982 and charged in connection with a cocaine-trafficking conspiracy and was awaiting trial. Tony Musitano befriended inmate Billy Rankin at Millhaven Institution in Kingston who was due to be released in December that year. Giuseppe Avignone, nephew of Tony and Domenic Musitano, often visited Tony in prison to discuss details of the plot, which were secretly recorded by the police. Rankin was released on December 7, and given "the okay" by Domenic Musitano. On December 10, 1983, Racco got into a car in front of his Mississauga apartment with Rankin, Domenic Musitano and Peter Majeste, thinking it was to discuss a potential drug trade, but was taken to a railway track and killed. In March 1984, Domenic and Tony Musitano, Avignone and Rankin were arrested. Domenic Musitano received six years for being an accessory after the fact to murder. Anthony Musitano, already in prison on the bombing charges, was sentenced to 12 years concurrently, Avignone got five years and Rankin was sentenced to 12 years, all three pleading guilty to conspiracy to commit murder.

The Siderno mob in Southern Ontario was at the centre of a criminal business such as drug trafficking, cigarette smuggling, extortion, and gambling. The organisation managed to gain high levels of income from these activities in Canada, but the affiliated persons used to maintain tight links with the small and poor town of Siderno. In fact the organisation of the group was controlled from Siderno or in accordance with clans based there.