The person was in their 80s and lived in Lake County, Illinois.
They developed symptoms in the middle of this month and died soon after.
The Illinois Health Department says nine people across the state have come down with the virus so far this year.
West Nile Virus is typically spread through mosquito bites.
People older than 50 and immunocompromised individuals are at higher risk for severe illness from West Nile Virus.
SEE ALSO | Dr. Anthony Fauci was hospitalized with West Nile virus and is now recovering at home