The community of Larsmo was founded in 1867. Larsmo is made up of 360 isles and islands with a shoreline that is nearly 500 km. It is bounded by Lake Larsmo in the east and the Gulf of Bothnia in the west, the City of Karleby in the north and the City of Jakobstad in the south. The road of the Seven Bridges runs through Larsmo, connecting it with the rest of the world.

The largest islands are Larsmo and Eugmo and the main residential areas are Risö, Holm, Eugmo and Bosund. The community encompasses 142 km² and has a population of 5 347. A large part of the population commutes to the neighboring municipalities.

The industrial structure of Larsmo has gone through major changes since the 1990s. The importance of traditional industries like fishing, hunting and agriculture has diminished. Today, the economic structure is based on the service industry and small, local industries. The boatbuilding industry is of utmost importance.