Creates the Back-to-School Sales Tax Holiday Act. Provides that no sales tax shall be imposed on eligible merchandise purchased by any individual or entity in the State of Illinois during the sales tax holiday period. Provides that the sales tax holiday period is the period beginning at 12:01 a.m. on the first Friday in August and ending at 11:59 p.m. on the following Sunday. Provides that "sales tax" means the taxes imposed under the Use Tax Act, the Service Use Tax Act, the Service Occupation Tax Act, and the Retailers' Occupation Tax Act. Effective immediately.