This is a list of Illinois county name etymologies. Many counties in Illinois were named for early American leaders, especially of the American Revolutionary War, as well as soldiers from the Battle of Tippecanoe and the War of 1812. Several are named for natural features or counties in other states.

• Adams County is named for U.S. President John Quincy Adams
• Alexander County is named after area pioneer and Illinois state legislator William M. Alexander .
• Bond County is named after Shadrach Bond, the first Governor of Illinois.
• Boone County is named after frontiersman Daniel Boone.
• Brown County is named after Gen. Jacob Brown, a soldier in the War of 1812.
• Bureau County is named for Pierre de Bureo , a Frenchman who traded with local Native Americans.
• Calhoun County is named for U.S. Vice President John C. Calhoun.
• Carroll County is named for Charles Carroll of Carrollton, the last surviving signer of the U.S. Declaration of Independence.
• Cass County is named for U.S. Secretary of War and State, Lewis Cass.
• Champaign County is named after Champaign County, Ohio.
• Christian County is named after Christian County, Kentucky.
• Clark County is named after American Revolutionary War leader George Rodgers Clark, who captured important bases in Illinois Country during the war.
• Clay County is named after U.S. Speaker of the House Henry Clay.
• Clinton County is named for DeWitt Clinton, a Governor of New York.
• Coles County is named after Edward Coles , the second Governor of Illinois
• Cook County is named after Daniel Pope Cook, first attorney general of Illinois.
• Crawford County is named after U.S. Secretary of War William H. Crawford.
• Cumberland County is named for either the Cumberland River or the Cumberland Road.
• DeKalb County is named for Johann de Kalb, a hero of the American Revolutionary War.
• De Witt County is named for DeWitt Clinton, a Governor of New York.
• Douglas County is named after U.S. Senator from Illinois Stephen A. Douglas.
• DuPage County is named after the DuPage River.
• Edgar County is named after local pioneer John Edgar .
• Edwards County is named after Ninian Edwards, the last Governor of the Illinois Territory.
• Effingham County is named for Lord Edward Effingham , who resigned his commission as general in the British army in 1775, refusing to serve in the war against the colonies.
• Fayette County is named after the Marquis de la Fayette.
• Ford County is named after Governor of Illinois Thomas Ford.
• Franklin County is named after Founding Father Benjamin Franklin.
• Fulton County is named after Robert Fulton, the steamboat inventor.
• Gallatin County is named after U.S. Secretary of the Treasury Albert Gallatin.
• Greene County is named after American Revolutionary War leader Nathanael Greene.
• Grundy County is named after U.S. Attorney General Felix Grundy.
• Hamilton County is named after Founding Father Alexander Hamilton.
• Hancock County is named after Founding Father John Hancock.
• Hardin County is named after Hardin County, Kentucky.
• Henderson County is named after Henderson County, Kentucky.
• Henry County is named after early American statesman Patrick Henry.
• Iroquois County is named after the Iroquois Native American people.
• Jackson County is named after U.S. President Andrew Jackson.
• Jasper County is named after William Jasper, a hero of the American Revolutionary War.
• Jefferson County is named after U.S. President Thomas Jefferson.
• Jersey County is named after the U.S. state of New Jersey.
• Jo Daviess County is named after Joseph Hamilton Daviess , a soldier killed at the Battle of Tippecanoe.
• Johnson County is named after U.S. Vice President Richard Mentor Johnson.
• Kane County is named after U.S. Senator Elias Kane.
• Kankakee County is named after the Kankakee River.
• Kendall County is named after U.S. Postmaster General Amos Kendall.
• Knox County is named after American Revolutionary War general Henry Knox.
• La Salle County is named after explorer René Robert Cavelier, Sieur de La Salle.
• Lake County is named after the many small lakes in and around the county.
• Lawrence County is named after James Lawrence, commander of the USS Chesapeake.
• Lee County is named after American Revolutionary War leader Lighthorse Harry Lee.
• Livingston County is named after U.S. Secretary of State Edward Livingston.
• Logan County is named after John Logan, father of U.S. Senator and GAR leader John A. Logan.
• Macon County is named after American Revolutionary War figure Nathaniel Macon.
• Macoupin County is named for a Native American word meaning white potato.
• Madison County is named for U.S. President James Madison.
• Marion County is named for Francis Marion, the American Revolutionary War fighter known as the "Swamp Fox."
• Marshall County is named after U.S. Chief Justice John Marshall.
• Mason County is named after Mason County, Kentucky.
• Massac County is named after Fort Massac .
• McDonough County is named after Commodore Thomas McDonough
• McHenry County is named after Gen. William McHenry .
• McLean County is named after U.S. Senator John McLean.
• Menard County is named after Illinois lieutenant governor Pierre Menard .
• Mercer County is named after American Revolutionary War leader Hugh Mercer.
• Monroe County is named after U.S. President James Monroe.
• Montgomery County is named after American Revolutionary War general Richard Montgomery.
• Morgan County is named after American Revolutionary War leader and Congressman Daniel Morgan.
• Moultrie County is named after William Moultrie, an American Revolutionary War general and Governor of South Carolina.
• Ogle County is named after politician Joseph Ogle .
• Peoria County is named for the Native American Peoria people.
• Perry County is named after Commodore Oliver H. Perry.
• Piatt County is named after John Piatt , the first county sheriff.
• Pike County is named after explorer Zebulon Pike.
• Pope County is named after Judge Nathaniel Pope.
• Pulaski County is named after Kazimierz Pulaski, a Polish-born American Revolutionary War leader.
• Putnam County is named after Israel Putnam.
• Randolph County is named after Beverly Randolph .
• Richland County is named after American Revolutionary War leader Richland County, Ohio.
• Rock Island County is named after Rock Island, an island in the Mississippi River.
• Saline County is named for the salt springs which are found in the county.
• Sangamon County is named after the Sangamon River.
• Schuyler County is named after American Revolutionary War general Philip Schuyler.
• Scott County is named after a local pioneer family named Scott.
• Shelby County is named after Isaac Shelby, a Governor of Kentucky.
• St. Clair County is named after "Governor St. Clair," probably Arthur St. Clair, governor of the Northwest Territory.
• Stark County is named after John Stark, a soldier of the French and Indian Wars and the American Revolutionary War.
• Stephenson County is named after Benjamin Stephenson , an adjutant general of Illinois Territory.
• Tazewell County was named for Littleton Waller Tazewell, a Governor of Virginia.
• Union County was named for the federal union which was threatened by the American Civil War.
• Vermilion County is named for the Vermilion River and the Little Vermilion River , both of which run through it.
• Wabash County is named for the Wabash River.
• Warren County is named for Joseph Warren, likely the first military officer to die for the Continentals in the American Revolutionary War.
• Washington County is named for U.S. President George Washington.
• Wayne County is named for Gen. "Mad" Anthony Wayne.
• White County is named for Leonard White , who was killed at the Battle of Tippecanoe.
• Whiteside County is named for Samuel Whiteside , a soldier in the War of 1812 and the Black Hawk War
• Will County is named for Conrad Will , a local politician.
• Williamson County is named for Williamson County, Tennessee.
• Winnebago County is named for the Winnebago Native American people.
• Woodford County is named after Woodford County, Kentucky.

Source

• Illinois Trails Presents County Facts

See also

• Illinois
• List of Illinois counties
• Lists of U.S. county name etymologies
• County (United States)