The incident occurred at a caravan park in Le Bouveret, a town at the eastern end of Lake Geneva, on Saturday night, cantonal police said in a statement.
The toddler was found in the Tové canal around 7pm about 15 minutes after a member of his family reported to emergency officials that he was missing, police said in a news release.
The boy had been playing in Les Carettes, a private campground for caravans and trailers, close to two canals, according to an online report from local newspaper Le Nouveilliste.
His lifeless body was pulled from the water just a few metres from his family’s mobile home, the newspaper said.
Attempts to resuscitate him by ambulance attendants were unsuccessful, police said.
Le Nouvelliste said tourists and law enforcement officials responded to the report of the missing child and quickly discovered him.
“I want to thank all the people who mobilized for us,” the boy’s mother is quoted as telling the newspaper.
“But today, I do not have the strength to say more.”
Prosecutor Frédéric Gisler has opened an investigation into what appears to have been a tragic accident, Le Nouvelliste said.
The caravan park where the incident occurred, one of three in the region, is located between the Tové and Bouverette canals.