Create your Illinois sublease agreement, and sublet your property. Rent your unit to a subtenant with a sublease agreement form.A sublease agreement is a rental contract used for rerenting a currently leased unit to a new tenant. An Illinois sublease agreement is a contract in which an existing tenant (sub-lessor) and a third-party (the sub-lessee) establish a rental arrangement. Sample Illinois Agreement to Sublease. This resource provides an example of what a sublease in Illinois looks like. Download. Our Chicago Sublease Agreement is tailored for tenants in Chicago, Illinois, who want to sublease their rental property. ☐ Tenant requires Landlord's written approval to sublet the Premises. In the event that the Original. Lease. Tenant entered into a _____ dated ______ ___, 20___ with ______ ("Landlord") for the rent and use of the Premises ______ (the "Original Lease").