High Quality Content by WIKIPEDIA articles! Vandalia is a city in Montgomery County, Ohio, United States, and a suburb of Dayton. Its population was 15,246 during the 2010 census. The James M. Cox Dayton International Airport is located in the city. In addition to being the home of the Dayton International Airport, Vandalia lies at the crossroads of I-75 and I-70, making it a major hub for business.