A third victim died later from injuries sustained in the crash.
The accident took place on route 70 between Vikarbyn and Rättsvik around 3.30pm.
A 65-year-old couple, who were driving in one of the cars, died on the scene. Occupants of the second car included an 80-year-old woman, a 60-year-old man, as well as a 25-year-old man.
All three were taken to hospital in nearby Mora. Later in the evening, the hospital announced that the woman had died from her injuries. The two men received less serious injuries, but remained in hospital for observation.
The cause of the accident is not yet known, although icy conditions have been noted on roads in Dalarna county over the course of the day.
“There have been icy patches in some places, but I can’t say if that was the case there or if it was the cause of the accident,” said commanding officer Yasemin Mollaoglu to the TT news agency.
Subsequent reports indicated that the stretch of road where the accident took place wasn’t icy at the time of the crash.