Champaign, IL Airport (CMI-University Of Illinois Urbana-Champaign Williard). So much to see, so little time. Before you set off in your rental car and explore this amazing place, we'll get you up to speed on the basics.Champaign, IL Airport (CMI-University Of Illinois Urbana-Champaign Williard) is located 6 miles to the south from downtown Champaign.