St1 Oy is a Finnish energy company owning the St1 service stations’ chain in Finland, Sweden, Norway and Poland. The company was established in 1995 under the name Greenergy Baltic Oy. In 1997, the St1 chain was established in Finland. In 2000 Greenergy Baltic changed its name to Green. In the same year, it purchased the St1 chain.

In addition the service stations, the St1 Oy owns the St1 Refinery in Gothenburg, produces ethanol fuel at six bioethanol plants in Finland, and generates and sells electricity. Together with the SOK Group it owns the wind farms developer TuuliWatti Oy.