This is a list of law enforcement agencies in the state of Illinois.
According to the US Bureau of Justice Statistics' 2018 Census of State and Local Law Enforcement Agencies, the state had 846 law enforcement agencies employing 48,240 sworn police officers, about 379 for each 100,000 residents.2018 Census of State and Local Law Enforcement Agencies, by Andrea M. Gardner and Kevin M. Scott, Ph.D., US Department of Justice, Office of Justice Programs, Bureau of Justice Statistics, October 2022
State agencies Illinois Attorney General's Office Department of Investigations Illinois Attorney General Police Illinois Commerce Commission Police Illinois Department of Corrections Illinois Department of Human Services Police Department Illinois Department of Natural Resources Illinois Conservation Police Illinois Department of Revenue Police Bureau of Criminal Investigations Illinois Gaming Board Illinois Law Enforcement Training and Standards Board Illinois Secretary of State Illinois Secretary of State Capitol Police Illinois Secretary of State Police Illinois State Fire Marshal Arson Investigation Illinois State Police
County agencies Sheriff's Offices
Adams County Sheriff's Office Alexander County Sheriff's Office Bond County Sheriff's Office Boone County Sheriff's Office Brown County Sheriff's Office Bureau County Sheriff's Office Calhoun County Sheriff's Office Carroll County Sheriff's Office Cass County Sheriff's Office Champaign County Sheriff's Office Christian County Sheriff's Office Clark County Sheriff's Office Clay County Sheriff's Office Clinton County Sheriff's Office Coles County Sheriff's Office Cook County Sheriff's Office Crawford County Sheriff's Office Cumberland County Sheriff's Office DeKalb County Sheriff's Office Dewitt County Sheriff's Office Douglas County Sheriff's Office DuPage County Sheriff's Office Edgar County Sheriff's Office Edwards County Sheriff's Office Effingham County Sheriff's Office Fayette County Sheriff's Office Ford County Sheriff's Office Franklin County Sheriff's Office Fulton County Sheriff's Office Gallatin County Sheriff's Office Greene County Sheriff's Office Grundy County Sheriff's Office Hamilton County Sheriff's Office Hancock County Sheriff's Office Hardin County Sheriff's Office Henderson County Sheriff's Office Henry County Sheriff's Office Iroquois County Sheriff's Office Jackson County Sheriff's Office Jasper County Sheriff's Office Jefferson County Sheriff's Office Jersey County Sheriff's Office Jo Daviess County Sheriff's Office Johnson County Sheriff's Office Kane County Sheriff's Office Kankakee County Sheriff's Office Kendall County Sheriff's Office Knox County Sheriff's Office LaSalle County Sheriff's Office Lake County Sheriff's Office Lawrence County Sheriff's Office Lee County Sheriff's Office Livingston County Sheriff's Office Logan County Sheriff's Office Macon County Sheriff's Office Macoupin County Sheriff's Office Madison County Sheriff's Office Marion County Sheriff's Office Marshall County Sheriff's Office Mason County Sheriff's Office Massac County Sheriff's Office Mc Donough County Sheriff's Office Mc Henry County Sheriff's Department Mc Lean County Sheriff's Office Menard County Sheriff's Office Mercer County Sheriff's Office Monroe County Sheriff's Office Montgomery County Sheriff's Office Morgan County Sheriff's Office Moultrie County Sheriff's Office Ogle County Sheriff's Office Peoria County Sheriff's Office Perry County Sheriff's Office Piatt County Sheriff's Office Pike County Sheriff's Office Pope County Sheriff's Office Pulaski County Sheriff's Office Putnam County Sheriff's Office Randolph County Sheriff's Office Richland County Sheriff's Office Rock Island County Sheriff's Office Saint Clair County Sheriff's Office Saline County Sheriff's Office Sangamon County Sheriff's Office Schuyler County Sheriff's Office Scott County Sheriff's Office Shelby County Sheriff's Office Stark County Sheriff's Office Stephenson County Sheriff's Office Tazewell County Sheriff's Office Union County Sheriff's Office Vermilion County Sheriff's Office Wabash County Sheriff's Office Warren County Sheriff's Office Washington County Sheriff's Office Wayne County Sheriff's Office White County Sheriff's Office Whiteside County Sheriff's Office Will County Sheriff's Office Williamson County Sheriff's Office Winnebago County Sheriff's Office Woodford County Sheriff's Office
County Forest Preserve police departments Forest Preserve District of Cook County, Department of Law Enforcement Forest Preserve District of DuPage County, Law Enforcement Department Forest Preserve District of Kane County, Public Safety Department Lake County Forest Preserve District, Public Safety Department, aka Ranger Police Department McHenry County Conservation District Police, Law enforcement for forest preserves in McHenry County Forest Preserve District of Will County, Police Department
Other county departments Cook County State's Attorneys Office, Investigations Unit Cook County Health and Hospitals System Police Department McHenry County Conservation Police Department Vermilion County Conservation Police Department
Municipal agencies
Abingdon Police Department Addison Police Department Albany Police Department Albers Police Department Albion Police Department Aledo Police Department Alexis Police Department Algonquin Police Department Alma Police Department Alorton Police Department Alpha Police Department Alsip Police Department Altamont Police Department Alton Police Department Altona Police Department Alvin Police Department Amboy Police Department Andalusia Police Department Anna Police Department Annawan Police Department Antioch Police Department Apple River Police Department Arcola Police Department Argenta Police Department Arlington Heights Police Department Armington Police Department Aroma Park Police Department Arthur Police Department Ashkum Police Department Ashland Police Department Ashley Police Department Ashton Police Department Assumption Police Department Astoria Police Department Athens Police Department Atkinson Police Department Atlanta Police Department Atwood Police Department Auburn Police Department Augusta Police Department Aurora Police Department Ava Police Department Aviston Police Department Avon Police Department Baldwin Police Department Bannockburn Police Department Barrington Police Department Barrington Hills Police Department Barrington-Inverness Police Department Barry Police Department Bartlett Police Department Bartonville Police Department Batavia Police Department Bath Police Department Baylis Police Department Bayview Gardens Police Department Beardstown Police Department Beckemeyer Police Department Bedford Park Police Department Beecher Police Department Belgium Police Department Belleville Police Department Bellflower Police Department Bellwood Police Department Belvidere Police Department Bement Police Department Benld Police Department Bensenville Police Department Benton Police Department Berkeley Police Department Berwyn Police Department Bethalto Police Department Bethany Police Department Blandinsville Police Department Bloomingdale Police Department Bloomington Police Department Blue Island Police Department Blue Mound Police Department Bluffs Police Department Bolingbrook Police Department Bonnie Police Department Bourbonnais Police Department Bradford Police Department Bradley Police Department Braidwood Police Department Breese Police Department Bridgeport Police Department Bridgeview Police Department Brighton Police Department Broadview Police Department Brocton Police Department Brookfield Police Department Brooklyn Police Department Brookport Police Department Brownstown Police Department Buckner Police Department Buda Police Department Buffalo Grove Police Department Buffalo-Mechanicsburg Police Department Bull Valley Police Department Buncombe Police Department Bunker Hill Police Department Burbank Police Department Bureau Police Department Burnham Police Department Burr Ridge Police Department Bushnell Police Department Byron Police Department Cahokia Police Department Cairo Police Department Calumet City Police Department Calumet Park Police Department Cambria Police Department Camp Point Police Department Campton Hills Police Department Canton Police Department Carbondale Police Department Carlinville Police Department Carlyle Police Department Carmi Police Department Carol Stream Police Department Carpentersville Police Department Carrier Mills Police Department Carrollton Police Department Carterville Police Department Carthage Police Department Cary Police Department Casey Police Department Caseyville Police Department Catlin Police Department Cave-In-Park Police Department Cedar Point Police Department Cedarville Police Department Central City Police Department Centralia Police Department Centreville Police Department Cerro Gordo Police Department Chadwick Police Department Champaign Police Department Chandlerville Police Department Channahon Police Department Chapin Police Department Charleston Police Department Chatham Police Department Chebanse Police Department Chenoa Police Department Cherry Police Department Cherry Valley Police Department Chester Police Department Chesterfield Police Department Chicago Heights Police Department Chicago Police Department Chicago Ridge Police Department Chillicothe Police Department Chrisman Police Department Christopher Police Department Cicero Police Department Cissna Park Police Department Clarendon Hills Police Department Clayton Police Department Clinton Police Department Coal City Police Department Coal Valley Police Department Cobden Police Department Coffeen Police Department Colchester Police Department Colfax Police Department Collinsville Police Department Colona Police Department Columbia Police Department Cordova Police Department Cortland Police Department Coulterville Police Department Country Club Hills Police Department Countryside Police Department Cowden Police Department Crainsville Police Department Creal Springs Police Department Crest Hill Police Department Crestwood Police Department Crete Police Department Creve Coeur Police Department Crossville Police Department Crystal Lake Police Department Cuba Police Department Cutler Police Department Cypress Police Department Dallas City Police Department Dalzell Police Department Dana Police Department Danvers Police Department Danville Police Department Darien Police Department De Pue Police Department Decatur Police Department Deer Creek-Goodfield Police Department Deerfield Police Department Dekalb Police Department Delavan Police Department DePue Police Department Des Plaines Police Department DeSoto Police Department Divernon Police Department Dixmoor Police Department Dixon Police Department Dolton Police Department Dongola Police Department Donnellson Police Department Dowell Police Department Downers Grove Police Department Downs Police Department Du Quoin Police Department Dunfermline Police Department Dupo Police Department Durand Police Department Dwight Police Department Earlville Police Department East Alton Police Department East Carondelet Police Department East Dubuque Police Department East Dundee Police Department East Galesburg Police Department East Hazel Crest Police Department East Moline Police Department East Peoria Police Department East St Louis Police Department Easton Police Department Edinburg Police Department Edwardsville Police Department Effingham Police Department El Paso Police Department Elburn Police Department Eldorado Police Department