The S Group (Finnish: S-ryhmä, Swedish: S-gruppen) is a Finnish retailing cooperative organisation with its head office in Helsinki. Founded in 1904, it consists of 19 regional cooperatives operating all around Finland in addition to SOK, Suomen Osuuskauppojen Keskuskunta (The Central Finnish Cooperative Society). S Group operates in the markets for groceries, consumer durables, service station, hotel and restaurant services. It is engaged in close competition with Kesko, with which it shares an oligopolistic position in many of the markets it operates in.
The group has businesses in Finland and Estonia. The S Group also had businesses in Latvia and Lithuania, but announced withdrawal from these markets in May 2017. It also withdrew from the Russian market in 2022.