The crash happened around 6:40 Thanksgiving night in the Town of Grant.
According to investigators a car headed south on County Highway G hit a horse-drawn buggy.
A 23-year-old Marion man and a 21-year-old Marion woman riding in the buggy were taken to a hospital with non-life threatening injuries.
The man driving the car was arrested on suspicion of operating under the influence, 3rd offense.
The names of the victims have not been released.