| # | Company | Employees |
|---|---|---|
| 1 |
O'Reilly Auto Partsoreillyauto.com
A leading retailer in the automotive aftermarket industry with over 6,000+ locations, committed to serving customers, community, and team members |
84,000 |
| 2 |
MassMutualmassmutual.com
Providing mutual life insurance and financial security services focused on community support, shared dependence, and long-term happiness. |
13,000 |
| 3 |
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 |
| 4 |
Bass Pro Shopsbasspro.com
Premier outdoor and conservation company offering destination retail, boats, resorts, and nature experiences, all while promoting conservation and community impact |
10,126 |
| 5 |
Baystate Healthbaystatehealth.org
Largest healthcare organization in western Massachusetts providing quality, compassionate care across hospitals, improving community health and economic impact. |
6,269 |
| 6 |
Missouri State Universitymissouristate.edu
The company focuses on community engagement, ethical leadership, and cultural competence as part of Missouri State's public affairs mission |
5,090 |
| 7 |
CoxHealthcoxhealth.com
A leading healthcare provider in southwest Missouri with six hospitals, 80+ clinics, 5 ERs, and 13,000+ employees dedicated to improving community health |
4,842 |
| 8 |
Prime Inc.primeinc.com
A successful transportation company offering refrigerated, flatbed, tanker, and intermodal services with a focus on safety, reliability, and employee satisfaction |
4,147 |
| 9 |
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 |
| 10 |
Big Y World Class Marketbigy.com
Family-owned supermarket chain in New England with over 70 locations, focused on providing world-class service and value for customers' at-home food needs |
3,604 |
| 11 |
Drug Enforcement Administrationdea.gov
Enforces controlled substance laws and regulations in the US, targets major drug traffickers, manages intelligence, seizes assets, and coordinates with law enforcement agencies. |
3,304 |
| 12 |
National Geospatial-Intelligence Agencynga.mil
Delivers world-class geospatial intelligence to warfighters, policymakers, and first responders to support national security priorities, disaster response, and global navigation efforts. |
3,199 |
| 13 |
Springfield Missouri Public Schoolssps.org
Leading public school district in Missouri, offering academic excellence to over 25,000 students through diverse programs including IB, WOLF, and Middle College |
2,901 |
| 14 |
Illinois Department of Human Servicesillinois.jobs2web.com
A large agency in Illinois with over 13,000 employees providing integrated services to promote self-sufficiency, independence, and health for individuals and communities |
2,733 |
| 15 |
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 |
| 16 |
Illinois Department of Transportationidot.illinois.gov
The company provides safe and cost-effective transportation services in Illinois, with a focus on enhancing quality of life, promoting economic prosperity, and respecting the environment |
2,103 |
| 17 |
Springfield Collegespringfield.edu
A university founded in 1885 with a focus on educating students in spirit, mind, and body for leadership and service to others |
2,003 |
| 18 |
UICGS / Bowhead Family of Companiesbowhead.com
A division of an Alaskan Native Corporation, offering premier support to defense and civilian government agencies through various services across the United States |
1,927 |
| 19 |
Springfield Clinicspringfieldclinic.com
Providing high-quality primary and specialized healthcare with advanced treatments and technologies, serving central Illinois communities with compassionate care. |
1,891 |
| 20 |
Crozer-Keystone Health Systemcrozerhealth.org
A leading health care provider offering a full spectrum of wellness, acute care, and rehabilitation services in Delaware County, PA |
1,684 |
| 21 |
SIU Medicinesiumed.edu
A leading medical school and clinical provider offering innovative medical education, research, and quality health care in diverse work environments |
1,597 |
| 22 |
Illinois Secretary of Stateilsos.gov
The Office of the Secretary of State in Illinois is a key government agency responsible for maintaining state records and providing important services to citizens |
1,545 |
| 23 |
Springfield Public Schools (Massachusetts)springfieldpublicschools.com
The company provides a world-class education system in Springfield, focusing on developing 21st-century leaders and preparing students for college and careers |
1,408 |
| 24 |
Ozarks Technical Community Collegeozarkstech.edu
The company provides accessible, high-quality, and affordable learning opportunities to transform lives and strengthen communities in their service area |
1,388 |
| 25 |
University of Illinois Springfielduis.edu
Educating public servants and leaders is a core focus of this university, which is part of the U of I system |
1,379 |
| 26 |
Roseburg Forest Productsroseburg.com
Roseburg Forest Products sustainably harvests timber, manufactures high-quality lumber and specialty wood products, and delivers them to customers across North America |
1,364 |
| 27 |
Behavioral Health Network, Inc (BHN)bhninc.org
Non-profit community behavioral health agency providing services to children and families with mental illness, substance use disorders, and intellectual disabilities in Western Mass since 1938 |
1,336 |
| 28 |
Salon Service Groupstore.salonservicegroup.com
Independent distributor of professional salon products, representing top manufacturers, offering education, competitive pricing, and marketing support to salon owners and professionals |
1,308 |
| 29 |
Western New England Universitywne.edu
A university in Springfield, Massachusetts that fosters hard-working, ambitious, and caring students with a strong entrepreneurial spirit to excel |
1,244 |
| 30 |
Springfield Public Schools District 186sps186.org
The company collaborates with families and community to empower students to become responsible lifelong learners and citizens in a diverse world |
1,229 |
| 31 |
Horace Mannhoracemann.com
Providing tailored insurance and financial products including auto, home, life insurance, and retirement solutions specifically for educators and families. |
1,224 |
| 32 |
PacificSource Health Planspacificsource.com
Provides medical and dental benefits, self-funded employee programs, Flexible Spending Accounts, Health Reimbursement Arrangements, and COBRA administration services for Northwest individuals and organizations. |
1,207 |
| 33 |
Andy's Frozen Custardeatandys.com
Family-owned business serving handcrafted frozen custard treats with speed and a smile, prioritizing product quality, customer service, and community involvement |
1,178 |
| 34 | 1,160 | |
| 35 |
Illinois Department of Children and Family Servicesdcfs.illinois.gov
Protecting children and supporting families by investigating and intervening in cases of suspected child abuse, offering help through a confidential hotline |
1,151 |
| 36 |
Phoenix Home Care and Hospicephoenixhomehc.com
A values-driven organization dedicated to improving quality of life, embracing challenges with compassion and promoting growth through continual learning and empathy |
1,148 |
| 37 |
Public Notary
Consumer service company based in Mansfield, Ohio, specialized in public notary services Located at 785 Marlow Pl |
1,145 |
| 38 |
Springfield Public Schools (Oregon)springfield.k12.or.us
Dedicated to student success, Springfield Public Schools prioritize individual needs, community involvement, and continuous learning for bright futures |
1,069 |
| 39 |
BKD CPAs & Advisorsforvismazars.us
Top-tier CPA and advisory firm providing comprehensive services including risk management, technology, wealth management, and forensic and valuation services to clients globally |
1,068 |
| 40 |
Center for Human Development (CHD)chd.org
A leading social service organization in Western Massachusetts and Connecticut, providing a wide range of community-oriented human services for those in need |
999 |
| 41 |
Burrell Behavioral Healthburrellcenter.com
A leading behavioral health center in Missouri, providing care for over 40,000 clients through a network of 400+ licensed providers |
988 |
| 42 |
Hiland Dairy Foodshilanddairy.com
This company delivers pure, wholesome milk and dairy products from farmer-owned farms to customers' tables without added growth hormones |
985 |
| 43 |
City of Springfield, Missourispringfieldmo.gov
The city of Springfield offers diverse attractions, dining options, and cultural activities, with various career opportunities, competitive pay, benefits, and community involvement |
972 |
| 44 |
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 |
| 45 |
Drury Universitydrury.edu
This company offers a unique academic experience called Drury Fusion, combining intellectual growth with technical skills for students in various programs |
902 |
| 46 |
Penmac Staffing Services, Inc.penmac.com
A staffing service offering temporary and long-term staffing, human resource services, payroll administration, benefits, screenings, and pre-employment assessments |
893 |
| 47 |
Great Southern Bankgreatsouthernbank.com
A multi-state bank offering comprehensive banking products and services, committed to building relationships with customers, communities, and shareholders |
890 |
| 48 |
Levi, Ray & Shoup, Inc. (LRS)lrs.com
Founded in 1979, this company provides innovative IT solutions globally with over 900 employees, offering equal employment opportunities and diversity |
867 |
| 49 |
Hawes Grouphawesgroup.ai
A family of companies offering services in collections, accounts receivables, business management, technology, finance, and marketing to help businesses succeed |
840 |
| 50 |
Wittenberg Universitywittenberg.edu
A Lutheran-affiliated liberal arts college in Southwest Ohio known for its excellent academic standards, strong athletic tradition, and welcoming atmosphere |
787 |
| 51 |
Lincoln Land Community Collegellcc.edu
An Illinois-based community college district offering a variety of educational programs and degrees, with a mission to transform lives through learning |
765 |
| 52 |
Illinois State Board of Educationisbe.net
Overseeing public education policies and programs to ensure every child receives quality education and opportunities for full potential development. |
746 |
| 53 |
Springfield Technical Community Collegestcc.edu
A technical community college offering comprehensive education in manufacturing, STEM, healthcare, business, social work, and liberal arts, with a focus on closing achievement gaps |
735 |
| 54 |
American International Collegeaic.edu
A private college in Springfield, MA offering comprehensive education in liberal arts, business, health sciences, and education, accredited by various organizations |
733 |
| 55 |
HouseKeeperhousekeeperapp.net
Housekeeper offers a software platform connecting cleaners and hosts for managing cleaning jobs, payments, scheduling, and reviews, with live Geo-Tracking feature |
714 |
| 56 |
Washington Gaswashingtongas.com
Regulated utility delivering safe, reliable natural gas service to over 1.3 million residential, commercial, and industrial customers in DC, Maryland, Virginia. |
695 |
| 57 |
Dennis Groupdennisgroup.com
A leading food and beverage design-build firm with a focus on quality work, client satisfaction, safety, innovation, and building strong relationships |
688 |
| 58 |
Nursing Home Managersnone
A central Illinois management firm specializing in the nursing home industry, providing specialized services for the management of nursing homes |
679 |
| 59 |
Clark State Collegeclarkstate.edu
A public higher education institution in Ohio offering certificates, associate, and bachelor's degrees in 131 academic areas with online programs |
653 |
| 60 |
City of Springfield, Massachusettsspringfield-ma.gov
This company is located in Springfield, MA, known for its historical significance and being the birthplace of Dr Seuss |
651 |
| 61 |
Illinois Department of Correctionsillinois.gov
A multicultural agency committed to diversity, equity, and inclusion, focusing on promoting positive change, reentry programs, and reducing victimization in Illinois |
650 |
| 62 |
Integrity Home Care + Hospicehs.bayada.com
The company partners with BAYADA Home Health Care to provide unmatched skill and compassion in delivering home health care services |
639 |
| 63 |
City Utilities of Springfieldcityutilities.net
A community-owned utility company in southwest Missouri providing electricity, natural gas, water, broadband, and transit services with competitive prices and hometown service |
624 |
| 64 |
The St. Jamesthestjames.com
The company offers premier sports, wellness, and entertainment experiences with state-of-the-art facilities, coaching programs, health services, dining, and retail options |
620 |
| 65 |
Illinois Army National Guardnationalguard.com
The Army National Guard serves communities, upholds traditions, and values commitment to country through a citizen-soldier tradition spanning centuries |
604 |
| 66 |
Hanson Professional Services Inc.hanson-inc.com
Employee-owned consulting firm offering engineering, planning, and allied services, with a focus on client success through hands-on project management |
594 |
| 67 | 594 | |
| 68 |
The Arc of the Ozarksthearcoftheozarks.org
A not-for-profit organization supporting individuals with disabilities through various services, including residential, education, training, and advocacy, to promote community integration and independence |
594 |
| 69 |
Convoy of Hopeconvoyofhope.org
Faith-based nonprofit organization focused on feeding the world through children's feeding programs, community outreach, and disaster response Providing help and hope to those in need |
593 |
| 70 |
The Larson Group (TLG Peterbilt)tlgtrucks.com
A top-performing dealer group for Peterbilt Motors, with 20+ locations providing award-winning products and services, focused on customer satisfaction and building strong relationships |
592 |
| 71 |
Murney Associates, Realtorsmurney.com
A leading real estate company in Southwest Missouri, locally owned with national recognition for award-winning performance, specializing in stress-free moves |
584 |
| 72 |
Evangel Universityevangel.edu
A Christian university in Springfield, Mo offering undergraduate and graduate programs preparing students for leadership roles in various sectors |
572 |
| 73 |
Southern Illinois University School of Medicinesiumed.edu
A growing medical school and clinical provider known for innovative education, cutting-edge research, and quality healthcare in diverse work environments |
551 |
| 74 |
Illinois Department of Innovation & Technology (DoIT)doit.illinois.gov
Empowers state agencies with modern technology solutions, delivers statewide technology, innovation and telecommunication services, manages the Illinois Century Network for reliable communication links. |
548 |
| 75 |
Timber Products Co.timberproducts.com
Manufacturer of wood products specializing in decorative wood panels with veneers and laminates Emphasizes environmental stewardship, quality, and sustainability |
548 |
| 76 |
Paul Mueller Companypaulmueller.com
Global supplier of stainless steel processing equipment for heating, cooling, and storage solutions in various industries such as agriculture, brewing, pharmaceuticals, and biotechnology |
525 |
| 77 |
Associated Electric Cooperative Inc.aeci.org
This company provides wholesale power to electric cooperatives in Missouri, northeast Oklahoma, and southeast Iowa, serving over 900,000 customers |
523 |
| 78 |
EFFINGHAM COUNTY SCHOOL DISTRICTeffinghamschools.com
A primary/secondary education institution located in Springfield, Georgia, providing educational services to students in Effingham County |
523 |
| 79 |
The Real Estate Groupdeniseholman.com
A real estate professional with extensive marketing experience offering personalized services to buyers and sellers for fast and successful transactions |
517 |
| 80 |
Crawford, Murphy & Tillycmtengr.com
An engineering and consulting firm established in 1946, specializing in providing superior infrastructure solutions and driving positive change through infrastructure |
515 |
| 81 |
Robertson County Schoolsrcstn.net
Educational institution in Robertson County, TN serving 11,500 students from Pre-K to 12th grade |
504 |
| 82 |
Little Sunshine's Playhouselittlesunshine.com
Providing a safe, nurturing, and enriching environment, this preschool offers a Reggio Emilia inspired curriculum with unique facilities and distinctive services |
491 |
| 83 |
Illinois Department of Revenuetax.illinois.gov
Administering Illinois tax laws, collecting revenues fairly and efficiently, providing funding and information to constituents, focusing on accuracy, innovation, and productivity |
489 |
| 84 |
City of Springfield, Oregonspringfield-or.gov
A municipal government in Springfield, Oregon with various departments providing services, governed by a City Manager and Council with community involvement #CommunityOfOpportunity |
484 |
| 85 |
Springfield City School Districtscsdoh.org
The Springfield City School District provides a diverse, innovative learning environment for 7,700 preK-12 students through personalized education options and academic growth opportunities |
478 |
| 86 |
White River Marine Groupwhiterivermg.com
The company is a leading manufacturer of fishing and recreational boats, ATVs, side-by-sides, kayaks, and provides financing solutions for outdoor recreational products |
473 |
| 87 |
Springfield, VT School Districtssdvt.org
The company focuses on revitalizing communities by supporting students and their educational journey one step at a time |
464 |
| 88 |
Illinois Environmental Protection Agencyepa.illinois.gov
This organization in Illinois aims to protect environmental quality and natural resources by working with businesses, governments, and citizens |
454 |
| 89 |
Farm Credit Financial Partners, Inc.financialpartners.com
A customer-owned service organization supporting agricultural credit associations with innovative technology products and services to improve lending for American agriculture |
443 |
| 90 |
Catalyst Acoustics Groupcatalystacoustics.com
Parent company of elite acoustic, seismic, vibration, and noise control businesses offering a wide range of solutions with unique brands and expertise |
440 |
| 91 |
Illinois Department of Natural Resourcesdnr.illinois.gov
This company manages, conserves, and protects Illinois' natural, recreational, and cultural resources, while promoting education, science, public safety, and economic benefits statewide |
415 |
| 92 |
Gun Owners Of Americagunowners.org
Advocating for the right to keep and bear arms without compromise, ensuring lawmakers understand and defend the Second Amendment |
415 |
| 93 |
MCKENZIE-WILLAMETTE MEDICAL CENTERmckweb.com
A 113-bed community hospital offering a range of medical services, including trauma care, cardiology, surgery, obstetrics, pediatrics, and rehabilitation Owned in part by physicians |
401 |
| 94 |
MGM Springfieldmgmspringfield.mgmresorts.com
A high-end resort and casino in downtown Springfield, MA with gaming, dining, entertainment, and event spaces, contributing to the city's revival |
400 |
| 95 |
Health New Englandhealthnewengland.org
A Springfield-based non-profit health plan offering a variety of healthcare plans in commercial, Medicaid, and Medicare markets, resolving a trademark dispute |
393 |
| 96 |
Digital Monitoring Productsdmp.com
A family-owned manufacturer of electronic burg/fire/access products, emphasizing quality, integrity, and strong dealer relationships to provide life-safety solutions |
380 |
| 97 |
Echo Electricechoelectric.com
A leading electrical supply company in the Midwest, providing quality products and services for over 85 years with a focus on customer satisfaction |
376 |
| 98 |
Illinois Department of Healthcare and Family Serviceshfs.illinois.gov
The company collaborates to provide Illinois residents with quality healthcare and support for fulfilling child support obligations to promote well-being |
370 |
| 99 |
Jordan Valley Healthjordanvalley.org
A Federally Qualified Health Center serving Southwest Missouri, providing primary medical, dental, vision, and behavioral health services through multiple clinic locations and mobile units |
369 |
| 100 |
CSLLCcsllcnow.com
A leading provider of customer engagement services for businesses, offering responsive and efficient customer service experiences while representing clients as brand ambassadors |
366 |
Turn this list into pipeline
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How this list is built
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.
The same list elsewhere in United States
- The largest companies in the United States 91,669
- The largest companies in California 12,813
- The largest companies in New York State 10,485
- The largest companies in Texas 8,086
- The largest companies in Florida 4,945
- The largest companies in Illinois 4,175
- The largest companies in Pennsylvania 3,110
- The largest companies in Massachusetts 3,093
- The largest companies in Georgia 2,632
- The largest companies in Ohio 2,618
- The largest companies in New Jersey 2,569
- The largest companies in Virginia 2,503
- The largest companies in Michigan 2,346
- The largest companies in North Carolina 2,174
- The largest companies in Alabama 1,806
- The largest companies in Washington State 1,785
- The largest companies in Colorado 1,774
- The largest companies in Minnesota 1,700
- The largest companies in Maryland 1,527
- The largest companies in Wisconsin 1,482
- The largest companies in New York 6,920
- The largest companies in San Francisco 2,030
- The largest companies in Houston 1,791
- The largest companies in Chicago 1,668