Fly Local. Fly Decatur. Skip the hassle and fly directly from the Decatur Airport to Chicago O’hare today! The Decatur Airport Terminal Building is a 24,000 sq. ft. ground level facility housing airline and car rental counters, ample seating for passengers & guests, baggage claim area, and administrative offices. Visitors and travelers will enjoy the convenience of close-in parking as well as long-term parking free of charge.