Daftar julukan kota di Illinois ini mengandung samaran, julukan, dan slogan yang disematkan kepada beberapa kota di Illinois (resmi dan tidak resmi) oleh pemerintah kota, masyarakat setempat, orang asing, badan pariwisata, atau kamar dagang. Julukan kota berperan sebagai perintis identitas lokal, membantu orang asing mengenali masyarakat setempat, atau mengajak orang berkunjung karena julukannya khas; mengangkat martabat daerah; dan mempersatukan masyarakat.[1] Julukan dan slogan yang berubah menjadi "ideologi atau mitos" baru[2] juga diyakini memiliki potensi ekonomi.[1] Potensi ekonominya sulit diukur,[1] tetapi ada beberapa kota yang memakai slogan baru untuk memasarkan/mencitrakan diri dan memanfaatkan potensi ekonomi tersebut.[2]
Beberapa julukan tidak resmi bersifat positif dan negatif. Julukan tidak resmi di bawah ini populer dan sudah lama digunakan.
^"History of Algonquin". Village of Algonquin, IL. 9 February 2009. Diarsipkan dari versi asli tanggal 3 August 2014. Diakses tanggal 14 January 2012.
^"Aurora History – A Rapidly Growing City". About Our City. City of Aurora, IL. Diarsipkan dari versi asli tanggal 29 July 2012. Diakses tanggal 14 January 2012. Later, when the City was the first in the United States to use electric lights for publicly lighting the entire City, it achieved the nickname of 'City of Lights'.
^Schielke, Jeffery. "Our Town". Batavia History. City of Batavia. Diarsipkan dari versi asli tanggal 17 October 2010. Diakses tanggal 14 January 2012.
^"Central Park skateboarders back to getting the boot – Mayor chases out those bored with their Fairview Park facility." Mike Frazier, Decatur Herald & Review, Saturday, November 11, 2006, p.A1
^"ADM lunch puts soy in spotlight – The company spreads the word about food's health benefits." Paul Brinkmann, Decatur Herald & Review, Saturday, November 20, 1999 p.A1
^Lombard InfoDiarsipkan 2010-05-27 di Wayback Machine., National University of Health Sciences, accessed April 21, 2007. "Held each year during the first three weeks in May, regardless of the vagaries of the growing season, Lilac Time is Lombard’s celebration of a 70-year-old horticultural tradition that has led to the town’s designation as “The Lilac Village,”"
^Morton Pumpkin Festival InformationDiarsipkan 2018-01-17 di Wayback Machine., Morton Chamber of Commerce, accessed April 21, 2007. "Morton is the "Pumpkin Capital of the World". Home of Nestle/Libby's pumpkin packing plant, 80% of the world's canned pumpkin is processed here."
^Another Gem City Landing?Diarsipkan 2007-09-27 di Wayback Machine., WGEM, April 10, 2007, accessed April 21, 2007. "QUINCY – It was an event that attracted thousands of people from around the world to the Gem City and then it moved to a different location -- Rantoul."