| # | Company | Employees |
|---|---|---|
| 1 |
Walgreenswalgreens.com
A leading retail pharmacy offering health and beauty products, with a focus on providing pharmacy services and a seamless omnichannel experience for customers |
90,723 |
| 2 |
United Airlinesunited.com
Leading airline with over 90,000 employees focused on customer service, sustainability, and teamwork, currently hiring 15,000 new team members in 2023 |
75,520 |
| 3 |
Allstateallstate.com
This company advocates for peace of mind, builds diverse teams, develops careers, and empowers people and communities through innovation and advocacy |
55,012 |
| 4 |
CommonSpirit Healthcommonspirit.careers
Building a healthier future for all through integrated health services, delivering patient encounters via clinics, care sites, hospitals, home-based services, and virtual care. |
48,074 |
| 5 |
Northern Trustnortherntrust.com
Global provider of innovative wealth management, asset servicing, and investment solutions for institutions, families, and individuals through diverse technology and financial expertise. |
30,965 |
| 6 |
Discover Financial Servicesdiscover.com
Provider of lending products and payment services enabling merchants, fintech companies, and consumers to access financial solutions and global card acceptance. |
21,937 |
| 7 |
Health Care Service Corporationhcsc.com
Provides health coverage for employers, individuals, and families, including Medicare and Medicaid plans, plus related health care products and services. |
21,090 |
| 8 |
Exelonexeloncorp.com
A leading utility company providing reliable and affordable energy to over 10 million customers in urban areas across multiple states, with a commitment to sustainability and community support |
20,291 |
| 9 |
Endeavor Healthendeavorhealth.org
Endeavor Health is a healthcare system in Illinois, uniting multiple hospitals to provide personalized patient experiences and world-class care |
16,454 |
| 10 |
Northwestern Medicinenm.org
Academic medical center combining research, teaching, and patient care with a large workforce across numerous regional locations and top-ranked hospitals. |
16,181 |
| 11 |
Rush University Medical Centerrush.edu
Academic medical center with hospital, health center, university offering medical, nursing education, research, residency programs, and community outreach services. |
12,484 |
| 12 |
OSF HealthCareosfhealthcare.org
Integrated health system with hospitals, home care, nursing colleges, digital health services, philanthropic foundation, and healthcare innovation investments. |
12,433 |
| 13 |
Hospital Sisters Health Systemhshs.org
Multi-institutional health system providing integrated, patient-centered care through hospitals, clinics, and physician partners in Illinois and Wisconsin. |
11,854 |
| 14 |
Advocate Health Careadvocatehealth.com
Integrated nonprofit health system providing clinical innovation, specialized care, extensive research, education, and community benefits across multiple U.S. states. |
11,676 |
| 15 | 11,608 | |
| 16 |
Zurich North Americazurichna.com
Provider of insurance solutions and services to businesses and individuals across various industries, including Fortune 500 companies. |
9,359 |
| 17 |
Transdev North Americatransdevna.com
Provides safe, reliable, and innovative transportation services including bus, rail, paratransit, autonomous vehicles, and maintenance across 45 US states. |
7,841 |
| 18 |
COUNTRY Financial庐countryfinancial.com
The company provides insurance and financial services across 19 states, helping clients protect assets and plan for the future |
7,668 |
| 19 |
Northwestern Memorial Hospitalnmh.org
A collaboration between healthcare and university partners, Northwestern Medicine aims to transform healthcare through research, teaching, and patient care excellence |
7,371 |
| 20 |
Ann & Robert H. Lurie Children's Hospital of Chicagoluriechildrens.org
Largest pediatric healthcare provider in the region, teaching partner of Northwestern University, nationally ranked in all pediatric specialties. |
7,202 |
| 21 |
Evernorth Health Servicesevernorth.com
Provider of adaptable pharmacy, care, and benefit services aiming to advance organizations and individuals through connected solutions |
7,188 |
| 22 |
Kemperkemper.com
Specialized insurer offering affordable personalized insurance solutions for individuals, families, and businesses through Auto and Life brands, serving over 49 million policies |
7,027 |
| 23 |
Carle Healthcarle.org
Integrated healthcare system combining clinical care, insurance, research, education, and philanthropy to improve patient outcomes and community health. |
6,896 |
| 24 |
Chicago Transit Authoritytransitchicago.com
Provides affordable and quality transit services connecting people, jobs, and communities across Chicago and 35 surrounding suburbs daily. |
6,500 |
| 25 |
UScellularuscellular.com
A leading wireless carrier empowering employees to make a positive impact on customers and communities, with a focus on career advancement and a supportive culture |
6,067 |
| 26 |
NorthShore University HealthSystemendeavorhealth.org
Integrated health system delivering personal patient care, convenient access, and pioneering medical services across multiple hospitals and clinics in Illinois. |
5,857 |
| 27 |
AMITA Healthadventhealth.com
Leading healthcare network in Illinois with 19 hospitals, 230+ outpatient sites, and a large provider network offering excellent care close to home |
5,689 |
| 28 |
Wintrust Financial Corporationwintrust.com
Provides banking, specialty finance, and wealth management services with a community-focused approach emphasizing integrity and client impact. |
5,374 |
| 29 | 5,359 | |
| 30 |
Bank of the Westbmo.com
Bank of the West, now part of the BMO Family, offers banking products and services through BMO Harris Bank NA Member FDIC |
4,892 |
| 31 |
CME Groupcmegroup.com
Global derivatives marketplace offering benchmark products across asset classes through electronic trading platforms and central counterparty clearing services for diverse financial risk management. |
4,781 |
| 32 |
Edward Hospitalendeavorhealth.org
United healthcare system focused on personal patient experiences, convenient access to world-class care, serving communities with hospitals and clinics. |
4,168 |
| 33 |
Presence Healthpresencehealth.org
A healthcare system in Illinois with 19 hospitals and over 230 sites, providing care to 43 million residents in the Chicagoland area |
4,089 |
| 34 |
Memorial Healthjobs.memorial.health
Leading healthcare organization in Illinois, providing state-of-the-art affiliates, dedicated to excellence in care, education, and research with a focus on employee development and national prominence |
4,012 |
| 35 |
Mercyhealth Wisconsin and Illinoismercyhealthsystem.org
Integrated health system providing world-class healthcare close to home, offering hospital, clinic, post-acute, and retail services with a commitment to making lives better |
3,927 |
| 36 |
First Transittransdevna.com
A global leader in mobility solutions, operating transportation systems, maintaining fleets, and delivering innovative solutions for cities, universities, companies, and airports |
3,864 |
| 37 |
Edward-Elmhurst Healthendeavorhealth.org
A unified health system in Illinois dedicated to providing personalized patient care and convenient access to world-class healthcare services |
3,425 |
| 38 |
Duly Health and Caredulyhealthandcare.com
Duly Health and Care is a leading medical group focused on helping individuals achieve their extraordinary health potential with over 900 physicians |
3,131 |
| 39 |
UI Healthhospital.uillinois.edu
This academic health enterprise in Illinois offers comprehensive care, education, and research to promote health equity and train healthcare leaders |
2,813 |
| 40 |
Loyola Medicineloyolamedicine.org
Integrated academic medicine provider with advanced technology, expert clinicians, and renowned centers for heart disease, cancer, organ transplant, orthopaedics, and neurological disorders |
2,653 |
| 41 |
The Options Clearing Corporation (OCC)theocc.com
World's largest equity derivatives clearing organization providing central counterparty settlement services for options, futures, and securities lending transactions to multiple trading platforms. |
2,620 |
| 42 |
HSHS St. John's Hospitalhshs.org
Regional medical center with 439 beds serving Central and Southern Illinois Part of a health care ministry with 14 hospitals, offering a high standard of care |
2,614 |
| 43 |
Advocate Christ Medical Center
A premier teaching hospital in Illinois with top-notch specialties in cancer care, cardiovascular services, transplantation, neurosciences, orthopedics, and women's health |
2,546 |
| 44 |
Invenergyinvenergy.com
Global innovators developing sustainable energy solutions through wind, solar, natural gas power generation, and advanced energy storage facilities Join us in building a greener future |
2,480 |
| 45 |
St. Joseph's Hospitalhshs.org
Healthcare facility in Clinton County offering inpatient, obstetric, surgical, and outpatient care, along with a state-of-the-art HealthPlex/YMCA for fitness and rehabilitation therapies |
2,435 |
| 46 |
Elmhurst Hospitalendeavorhealth.org
Endeavor Health provides a personalized patient experience and convenient access to world-class healthcare through a collaboration of several healthcare facilities |
2,255 |
| 47 |
Advocate Lutheran General Hospitaladvocatehealth.com
A top-ranked teaching hospital in Chicago with specialized pediatric care, trauma center, surgical excellence, stroke care, and nursing excellence |
2,185 |
| 48 |
Shirley Ryan AbilityLabsralab.org
Specializes in treating severe physical disabilities through integrated clinical care and research, improving recovery for complex conditions. |
2,124 |
| 49 |
Cook County Healthcookcountyhealth.org
Cook County Health provides comprehensive medical services for over 500,000 people annually in Chicago and suburban Cook County, regardless of ability to pay |
2,094 |
| 50 |
Northwest Community Healthcareendeavorhealth.org
Endeavor Health is a united healthcare system providing personalized patient experiences and world-class care through convenient access and collaboration #OurEndeavor |
1,916 |
| 51 |
CIBC USus.cibc.com
This company provides a range of banking services including commercial & personal banking, wealth management, and small business financial solutions They are an Equal Housing Lender and Member FDIC |
1,910 |
| 52 |
Southern Illinois Healthcaresih.net
A not-for-profit health system in southern Illinois with hospitals, a cancer center, trauma center, outpatient practices, and a commitment to community well-being |
1,894 |
| 53 |
Springfield Clinicspringfieldclinic.com
Providing high-quality primary and specialized healthcare with advanced treatments and technologies, serving central Illinois communities with compassionate care. |
1,891 |
| 54 | 1,866 | |
| 55 |
Swedish Hospitalswedishcovenant.org
Endeavor Health is a unified healthcare system providing personalized patient experiences and world-class care through collaboration between multiple hospitals |
1,862 |
| 56 |
Advocate Condell Medical Centeradvocatehealth.com
A leading medical center in the north suburbs providing high quality care for over 80 years, advocating for respectful engagement on social media |
1,858 |
| 57 |
Northwestern Medicine Central DuPage Hospitalcdh.org
A top-rated acute-care hospital in Winfield, IL providing quality healthcare services and nursing excellence to DuPage county residents and beyond |
1,852 |
| 58 |
Sinai Chicagosinaichicago.org
Committed to improving the health of diverse communities in Chicago, offering a range of inpatient/outpatient services, research programs, and social services |
1,851 |
| 59 |
Cook County Sheriff鈥檚 Officecookcountysheriffil.gov
A multi-faceted law enforcement agency in Cook County, Illinois, providing pre-detention facilities, court security, police services, and specialized units to residents |
1,834 |
| 60 |
Silver Cross Hospitalsilvercross.org
A leading healthcare provider offering quality and compassionate care through a modern facility, extensive medical staff, and advanced treatment options |
1,815 |
| 61 |
Blessing Healthblessinghealth.org
An integrated health system with hospitals, provider groups, specialty businesses, nursing college, and charitable foundation providing high-quality care to communities |
1,758 |
| 62 |
Cboe Global Marketscboe.com
A leading exchange network offering solutions for global derivatives, foreign exchange, digital assets, and securities trading, creating inclusive markets for all investors |
1,729 |
| 63 |
Metra Commuter Railmetra.com
A team connecting community members to important people and places through a reliable rail system spanning northeastern Illinois |
1,716 |
| 64 |
Federal Reserve Bank of Chicagochicagofed.org
Support economic growth and financial stability across the Seventh Federal Reserve District, including Iowa, Illinois, Indiana, Michigan, and Wisconsin. |
1,651 |
| 65 |
Rush Copley Medical Centerrush.edu
Provides quality healthcare services to residents, with 210 beds, 500 physicians, and an academic connection to Rush University System for Health. |
1,558 |
| 66 |
Riverside Healthcareriversidehealthcare.org
Integrated healthcare system providing inpatient and outpatient care, senior living communities, fundraising, fitness center, counseling programs, pharmacy services, and career opportunities in various healthcare fields |
1,538 |
| 67 |
Nicor Gasnicorgas.com
Leading natural gas distribution company in Illinois, ensuring safe and reliable gas delivery to over 22 million homes and businesses Committed to community, safety, and environmental stewardship |
1,521 |
| 68 |
DuPage Medical Groupdulyhealthandcare.com
Duly Health and Care is a multi-specialty medical group focused on helping individuals achieve extraordinary health and wellness through personalized care |
1,488 |
| 69 |
Consolidated Communicationsfidiumfiber.com
Unified residential, business, and wholesale fiber internet and network services under a single modern brand named Fidium. |
1,468 |
| 70 |
Superior Ambulance Servicesuperiorambulance.com
A family-owned EMS provider with over 1600 employees and 200 ambulances, offering services in Illinois, Indiana, and Michigan since 1959 |
1,398 |
| 71 |
Chicago Fire Departmentchicago.gov
This company is the largest fire department in the Midwest, providing fire safety, emergency care, and extinguishing fires while promoting public education and prevention initiatives |
1,392 |
| 72 |
United Ground Expressunitedgroundexpress.com
Providing a variety of airport operations services such as customer assistance, ramp service, and cabin appearance to multiple airlines across the United States |
1,378 |
| 73 |
National Express LLCsummitllc.com
North American transportation company focused on safety, quality, customer service, and positive employee relations across multiple locations. |
1,365 |
| 74 |
The Federal Savings Bankthefederalsavingsbank.com
Privately held veteran owned bank providing customized mortgage lending solutions across all fifty states through advanced technology and personalized one-to-one customer care. |
1,328 |
| 75 |
UW Health SwedishAmericancareers.uwhealth.org
A healthcare system in Wisconsin providing medical innovation and quality care to patients in Northern Illinois with access to UW Health experts |
1,314 |
| 76 |
Seasons Hospice & Palliative Careaccentcare.com
This company provides care services and has moved to a new LinkedIn page Follow them at wwwlinkedincom/companyaccentcare |
1,302 |
| 77 |
First American Bankfirstambank.com
Full-service banking institution providing personalized financial solutions, expert lending, and comprehensive wealth management services to individuals, families, and businesses across multiple locations. |
1,250 |
| 78 |
St. Elizabeth's Hospitalhshs.org
This state-of-the-art hospital and care center in Illinois provides accessible, patient-focused care through an integrated delivery model, guided by a Franciscan healing mission |
1,244 |
| 79 |
Advocate Illinois Masonic Medical Centeradvocatehealth.com
A Chicago-based 408-bed hospital offering comprehensive inpatient and outpatient medical services, including trauma care and neonatal intensive care |
1,237 |
| 80 |
Sarah Bush Lincolnsarahbush.org
A non-profit healthcare organization in Illinois with two hospitals, multiple clinics, advanced technology, engaged staff, community involvement, and commitment to excellence |
1,217 |
| 81 |
UChicago Medicine Ingalls Memorialuchicagomedicine.org
A century of pioneering clinical care and comprehensive outpatient centers with a focus on improving community health and partnering with UChicago Medicine |
1,197 |
| 82 |
Little Company of Mary Hospitalosfhealthcare.org
A not-for-profit Catholic hospital providing surgical, inpatient, and outpatient care with a deep-rooted compassion for patients' well-being and spiritual healing |
1,193 |
| 83 |
Advocate Medical Groupadvocatehealth.com
Integrated medical group in the Chicagoland area with primary care, specialty services, imaging, and community-based practices, committed to delivering outstanding healthcare outcomes and service |
1,152 |
| 84 |
MB Financial Bank53.com
This financial institution offers superior banking services as Fifth Third Bank Experience banking that is a step above the rest |
1,148 |
| 85 |
Byline Bankbylinebank.com
A long-standing resident of Chicago, this company offers innovative banking products and services dedicated to helping clients succeed They prioritize transparency, personalization, and keeping promises |
1,074 |
| 86 |
FairPoint Communicationsfairpoint.com
A leading broadband and business communications provider with advanced fiber optic network offering data, voice, video, cloud computing, and wireless backhaul solutions |
1,062 |
| 87 |
Northwestern Medicine Catherine Gratz Griffin Lake Forest Hospitallfh.org
A 201-bed community hospital part of Northwestern Medicine with 700 physicians, offering 90 medical specialties and recognized for nursing excellence |
1,038 |
| 88 |
Resurrection Health Carepresencehealth.org
A Catholic health system in Illinois with 12 hospitals, 27 long-term care facilities, physician offices, home care, hospice, and behavioral health services |
1,033 |
| 89 |
Advocate Children's Hospitaladvocatechildrenshospital.com
A leading pediatric hospital offering specialized care through a team of pediatricians, subspecialists, and advanced critical care services in the Chicago area |
998 |
| 90 |
Palos Healthnm.org
A healthcare provider in the Chicago suburbs with over 40 years of experience, focused on quality, respect, and trust in patient care |
980 |
| 91 |
Illinois Department of Public Health (IDPH)dph.illinois.gov
Protects health and improves lives for residents, preventing disease, safeguarding environment, promoting safe communities, and advocating for public health policies. |
967 |
| 92 |
Old Second National Bankoldsecond.com
This Chicago-area bank with over 150 years of experience prioritizes customer service, financial responsibility, and community growth in the region |
965 |
| 93 | 953 | |
| 94 |
QCR Holdings, Inc.qcrh.q4ir.com
Relationship-driven multi-bank holding company based in Moline, IL, serving various communities through subsidiary banks and commercial leasing operations |
937 |
| 95 |
Access Community Health Networkachn.net
A large network of federally-qualified health centers in Chicagoland area providing patient-centered, preventive, and primary care services to over 170,000 patients annually |
936 |
| 96 |
MacNeal Hospitalloyolamedicine.org
Providing quality, patient-centered care with inpatient, outpatient, and surgical services in the near west and southwest suburbs Values include quality, integrity, service, innovation, and transparency |
918 |
| 97 |
Metropolitan Water Reclamation District of Greater Chicagomwrd.org
Treating wastewater and managing stormwater to protect public health and the environment for Chicago and 128 suburban communities. |
906 |
| 98 |
Heartland Bank and Trust Companyhbtbank.com
Community bank offering financial services to commercial, retail, and municipal customers in Illinois and eastern Iowa Emphasis on local management and fast, efficient service |
899 |
| 99 |
First Midwest Bankoldnational.com
A merged bank holding company with $46 billion in assets, ranking among the top 35 in the US, maintaining a community banking heritage |
898 |
| 100 |
First Midfirstmid.com
A community-focused organization offering banking, insurance, wealth management, and agricultural services in Illinois, Missouri, and Texas Member FDIC and Equal Housing Lender |
895 |
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Every company on this list has a Tamtam company profile. The industry is the one the company gives on LinkedIn; categories such as SaaS or fintech are classified by Tamtam's AI from the company's website and LinkedIn page; and the headquarters city must match the company's own address. Companies are ranked by the number of employees on LinkedIn, and the list is refreshed every night. Classifications can be wrong, so treat the list as a starting point rather than an official ranking. Last updated Oct 24, 2026.
More company lists in Illinois
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