The governor of Illinois is the head of government of Illinois, and the various agencies and departments over which the officer has jurisdiction, as prescribed in the state constitution. It is a directly elected position, votes being cast by popular suffrage of residents of the state. The governor is responsible for enacting laws passed by the Illinois General Assembly. Illinois is one of 14 states that does not have a gubernatorial term-limit along with Connecticut, Idaho, Iowa, Massachusetts, Minnesota, New York, North Dakota, Texas, Utah, Washington, Wisconsin, District of Columbia, Vermont, New Hampshire and Puerto Rico. The governor is commander-in-chief of the state's land, air and sea forces when they are in state service.

The 43rd and current governor is J. B. Pritzker, a Democrat who took office on January 14, 2019.