Larsmo (Luoto in Finnish) is a municipality of Finland.
It is located in the province of Western Finland and is part of the Ostrobothnia region. The municipality has a population of 4,251 (2003) and covers an area of 170.34 kmē of which 32.59 kmē is water. The population density is 25.0 inhabitants per kmē.
The municipality is unilingually Swedish.
