Police say 24-year-old Megan Garven died after the vehicle in which she was traveling struck another in the city of Santiago.
Garven was from Philadelphia and had been teaching third grade at Santiago Christian School.
Injured were a fellow teacher, identified as Audrey Hickman of Chicago, and a student whose name was not released. The driver of the other vehicle in the accident late Tuesday was also injured.
The school canceled classes Wednesday.
Santiago is about 90 miles (150 kilometers) north of the capital, Santo Domingo.