Illinois residents enjoy free admission to shedd aquarium on select free days throughout the year! see the next illinois resident free days please note: a $3 transaction fee applies to illinois free day tickets reserved online.. Many chicago museums offer free admission days during the year, some open for all and some only available to illinois residents. see our list of participating museums, such as the field museum and the shedd aquarium, and the guidelines and schedules for the free admission dates in chicago.. Learn more about free days at shedd aquarium. a part of chicago since 1930, shedd aquarium welcomes 2 million guests annually for unforgettable encounters with 32,000 animals from the world�s aquatic environments including sea otters, dolphins, penguins and more..