ACS began as a dream in the hearts of concerned parents and Christian citizens in 1975. On January 7, 1975, about 40 people met to discuss the possibilities of developing a school that would be founded on the basis of Christian Education and Godly leadership. A board was formed, curriculum chosen, teachers selected, and on September 3, 1975, Aurora Christian School opened its doors with 82 students in grades K-9 in facilities loaned by Claim Street Baptist Church. By the end of the first year, enrollment had grown to 114 students.
The next year, the school expanded even further to include a preschool and 10th grade. Before long, the need for a new building was clear. God provided a large building on Illinois Avenue, and, after thousands of hours of volunteer work (and some contracted labor), Aurora Christian moved into their new facilities in 1976.