State Holidays 2025 Illinois. 2025 holidays in illinois office holidays provides calendars with dates and information on public holidays and bank holidays in key countries around the world. Illinois 2025 holidays, special days and observances :
Please check each individual secretary of state facility for the respective closing date.secretary of. Holidays illinois (united states) here you will find the public holidays for illinois of the current year ( 2024 ), of the following two years ( 2025 ), ( 2026 ), as well as of the past.