The executive branch is composed of six elected officers and their offices, as well as numerous other departments. Illinois is one of 26 states that elect their governor on the same ticket as their lieutenant governor. The six elected officers are:

• Governor
• Lieutenant Governor
• Attorney General
• Secretary of State
• Comptroller
• Treasurer

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. The term of office of governor of Illinois is 4 years, and there is no limit on the number of terms a governor may serve. Inauguration takes place on the second Monday in January following a gubernatorial election in November. A single term ends four years later.  Illinois is one of 13 states that does not have a gubernatorial term-limit. The governor is allowed the occupancy of the Illinois Governor's Mansion in Springfield, the state capital. Its first occupant was Governor Joel Aldrich Matteson, who took residence at the mansion in 1855. It is one of three oldest governor's residences in continuous use in the United States.

A governor is required to be:

• at least 25 years old
• a United States citizen
• a resident of Illinois for 3 years prior to election

If the incumbent governor is no longer able or permitted to fulfill the duties of the office of governor, the line of succession is as follows:

• Lieutenant Governor
• Attorney General of Illinois
• Secretary of State of Illinois

The lieutenant governor of Illinois is the second highest executive of the State of Illinois. In Illinois, the lieutenant governor and governor run on a joint ticket and are directly elected by popular vote. Gubernatorial candidates select their running mates when filing for office and appear on the primary election ballot together. The lieutenant governor of Illinois serves four-year terms. Inauguration takes place on the second Monday in January following a gubernatorial election.

Prior to the 1970 Constitution, governors and lieutenant governors were separately elected. The 1970 Constitution introduced joint elections for governor and lieutenant governor, though the candidates were nominated in separate primaries. Following the 1986 and 2010 elections, in which the Democratic nominees for Governor were forced to run with extreme or disfavored lieutenant-gubernatorial nominees, the Illinois General Assembly abolished the separate-primary requirement. The 2014 gubernatorial election was the first one to take place in which gubernatorial and lieutenant gubernatorial candidates ran on the same ticket in the primary election.

The lieutenant governor of Illinois handles a variety of responsibilities which have been delegated to the office via statute. These duties include serving as Chairman of the Governor's Rural Affairs Council, Chairman of Rural Bond Bank of Illinois, head of the Illinois Main Street Program, and Chairman of the Illinois River Coordinating Council.

In addition to these duties, the lieutenant governor can take on other duties as assigned by the governor or initiate duties of his or her own. The lieutenant governor also serves as a surrogate speaker for the governor around the state and as a representative for state government. The lieutenant governor is a member of the National Lieutenant Governors Association.

A lieutenant governor is required to be:

• at least twenty-five years old,
• United States citizen,
• a resident of Illinois for the three years previous to election,
• barred from other government positions during the term.

The Illinois attorney general is the highest legal officer of the state of Illinois in the United States. Originally an appointed office, it is now an office filled by statewide election. The attorney general is responsible for providing legal counsel for the various state agencies including the governor of Illinois and Illinois General Assembly, as well as conducting all legal affairs pertaining to the state.

The office of Illinois Attorney General was established on December 3, 1818, based on guidelines adopted by a state constitutional convention. The attorney general is second (behind the lieutenant governor) in the line of succession to the office of Governor of Illinois.

The Attorney General is required to be:

• at least 25 years old
• a United States citizen
• a resident of Illinois for 3 years prior to election

The attorney general's duties include advocating for the people of Illinois, working with the General Assembly to push for new legislation, and litigating to ensure that state laws are followed.

In addition, the state's attorney general Act specifies several duties, including:

• Represent the people of Illinois before the Supreme Court where the state or the people of the state are interested parties
• Prosecute all proceedings and actions in favor of the state
• Defend state officers acting in their official capacities in any actions or proceedings against them
• Consult with and advise the state's attorneys
• Investigate violations of all statutes that the attorney general has a duty to enforce
• Advise the governor and other state officers, and give written opinions on legal or constitutional matters when requested
• Give written opinions to the General Assembly or any of its committees when requested
• Prepare drafts of contracts in which the state is interested
• Attend, present evidence to, and prosecute indictments by the statewide grand jury
• Ensure the proper allocation of funds appropriated to public institutions, and prosecute breaches of trust

The attorney general also oversees the Public Access Counselor, which is responsible for enforcing the state's Freedom of Information Act and Open Meetings Act.

The secretary of state of Illinois is one of the six elected executive state offices of the government of Illinois, and one of the 47 secretaries of state in the United States. The Illinois secretary of state keeps the state records, laws, library, and archives, and is the state's corporation registration, vehicle registration and driver licensing authority. Illinois is one of only three states to put the secretary of state in charge of driver services, the other two being Maine and Michigan.

The Secretary of State is required to be:

• at least 25 years old
• a United States citizen
• a resident of Illinois for 3 years prior to election

The secretary of state, in accordance with the state constitution, is responsible for performing the following duties:

• Issues licenses to Illinois drivers and registers motor vehicles operated in the state.
• Keeper of the records of the official acts of the General Assembly, the official records of the executive branch, and the Great Seal of Illinois.
• Registerar of corporations and lobbyists, commissions notaries public, and regulates the securities industry, among connected responsibilities.
• Acts as the custodian of the Illinois State Capitol and all state buildings.
• Serves as the official depository of state agency and local government records that possess administrative, legal, or historic research value
• Oversees the state archives and the state library

The Comptroller is designated by law as the state's chief fiscal control officer and is responsible for the legal, efficient, and effective operations of state government. The Constitution of Illinois says the Comptroller: "shall maintain the State's central fiscal accounts, and order payments into and out of the funds held by the Treasurer."

The Comptroller is required to be:

• at least 25 years old
• a United States citizen
• a resident of Illinois for 3 years prior to election

The duties of the Comptroller include the following:

• Keeping and adjusting the statewide accounting system
• Signing paychecks and granting approval to electronic payments made by the state to its employees and creditors, monitors cash flow
• Preparing the state's annual comprehensive financial report, and providing monthly debt transparency reports to the General Assembly.
• Supervising local government finances in Illinois, including reviewing local government financial data, investigating instances of waste and fraud in local governments, and publishing an annual report summarizing the revenues, expenditures, fund balance, and debt of units of local government throughout the state.
• Regulating cemeteries under the Cemetery Care Act, and ensuring the fiduciary protection of cemetery care funds used for the care and maintenance of Illinois gravesites.

The Illinois State Treasurer’s Office is dedicated to protecting the state’s portfolio, ensuring the liquidity of all investments, and consistently producing earnings at or above industry standards. The Treasurer’s Office is committed to fulfilling this mission in a highly professional and ethical manner, while striving for transparency, efficiency, and preservation of public trust.

The Treasurer is required to be:

• at least 25 years old
• a United States citizen
• a resident of Illinois for 3 years prior to election