Police received a call on Tuesday afternoon after a person said they heard a splash which they said could have been a car falling into the water.
Divers later found two cars in the water. One had been there for some time and was lying on its roof, while the other held the two dead people.
“An elderly couple was found in the car,” said Per Sone of Stockholm Fire Brigade.
The other car was empty, and will not be salvaged, Sone added.