Sahalahti is a former municipality of Finland. It was located in the province of Western Finland and was part of the Pirkanmaa region. The municipality had a population of 2,229 (2003) and covered an area of 171.96 km² of which 35.09 km² was water. The population density was 16.3 inhabitants per km². Sahalahti joined to Kangasala on January 1, 2005. Its original administrative center was the village by the same name.
The municipality was unilingually Finnish.