| # | Company | Employees |
|---|---|---|
| 1 |
University of Illinois Urbana-Champaignillinois.edu
Leading public university with strong focus on education, research, global student opportunities, faculty innovation, and significant economic and community impact. |
24,692 |
| 2 |
University of Chicagouchicago.edu
A prestigious academic institution encouraging scholars and students to think critically, explore various disciplines, and challenge conventional ideas for global enrichment |
18,526 |
| 3 |
University of Illinois Chicagouic.edu
A large university in Chicago with 33,000 students, 12,000 employees, 16 colleges, and a public medical center |
17,943 |
| 4 |
Northwestern Universitynorthwestern.edu
Premier research university offering innovative teaching, pioneering research, and diverse, collaborative environments across multiple campuses near Chicago and Qatar. |
16,997 |
| 5 |
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 |
| 6 |
Southern Illinois University, Carbondalesiu.edu
Provides comprehensive academic instruction through associate, bachelor, master, doctoral, and professional degrees in law and medicine to students from across the globe. |
5,571 |
| 7 |
Argonne National Laboratoryanl.gov
National laboratory conducting advanced scientific and engineering research, developing innovative technologies, collaborating with industry and federal agencies for societal benefit. |
5,137 |
| 8 |
Northwestern University - The Feinberg School of Medicinefeinberg.northwestern.edu
A renowned medical school in Chicago offering MD programs, research, patient care, and community service to educate future physicians |
4,009 |
| 9 |
University of Illinois Systemuillinois.edu
The company is a flagship public university system in Illinois, offering excellence in education, healthcare, research, and economic development to the community |
2,436 |
| 10 | 2,376 | |
| 11 |
NORC at the University of Chicagonorc.org
An objective research organization partnering with clients to inform decisions on health, education, economy, and government programs for a better world |
2,285 |
| 12 |
Shirley Ryan AbilityLabsralab.org
Specializes in treating severe physical disabilities through integrated clinical care and research, improving recovery for complex conditions. |
2,124 |
| 13 |
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 |
| 14 |
Rosalind Franklin University of Medicine and Sciencerosalindfranklin.edu
graduate institution specializing in interprofessional health sciences education, offering medical, pharmacy, podiatry, and allied health professional degrees with research facilities |
1,400 |
| 15 |
Field Museumfieldmuseum.org
A forward-thinking scientific institution dedicated to exploring, protecting, and celebrating nature and culture through research, collections, public engagement, and education |
876 |
| 16 |
Chestnut Health Systemschestnut.org
A not-for-profit agency providing behavioral health services, addiction treatment, mental health counseling, housing, and supportive services with locations in Illinois and Missouri |
733 |
| 17 |
Northwestern University Pritzker School of Lawlaw.northwestern.edu
A prestigious law school in Chicago founded in 1859, offering rigorous legal education, access to top faculty, and practical experience opportunities |
624 |
| 18 |
Chicago Botanic Gardenchicagobotanic.org
A world-renowned living museum in Chicago area promoting plant connections, urban agriculture, education, conservation research, and horticulture beauty Nonprofit organization |
570 |
| 19 |
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 |
| 20 |
GTI Energygti.energy
Innovative technology development organization shaping global energy transitions with solutions leveraging gases, liquids, infrastructure, efficiency, and collaboration |
517 |
| 21 |
The Grainger College of Engineeringgrainger.illinois.edu
A top-ranked engineering program driving innovation, solving global challenges, and revolutionizing engineering education #wedotheimpossible |
490 |
| 22 |
Loyola University Chicago Stritch School of Medicineluc.edu
Educational institution focusing on medical education and training professionals to lead extraordinary lives while embracing diversity and values human dignity |
478 |
| 23 |
The Morton Arboretummortonarb.org
Internationally-recognized botanical garden dedicated to tree research, conservation, and education, offering classes, exhibits, and 16 miles of hiking trails |
397 |
| 24 |
UL Research Institutesul.org
A global safety science organization conducts trusted research to address public safety issues, develop standards, and promote sustainability |
389 |
| 25 |
University of Illinois College of Medicine Peoriapeoria.medicine.uic.edu
A medical school campus that educates medical students, physician residents, and physicians in a rigorous curriculum with hands-on experience and research opportunities |
386 |
| 26 |
Society of Actuariessoa.org
A leading actuarial professional organization providing education, research, and credentials to empower actuaries to manage risk and provide expert advice |
354 |
| 27 |
The Family Institute at Northwestern Universityfamily-institute.org
A leading behavioral health organization providing research, education, and counseling services to strengthen and heal individuals, couples, families, and children |
350 |
| 28 |
Institute of Design (ID)id.iit.edu
The company utilizes design as a tool to transform systems and create positive change in various industries, teaching others to do the same |
334 |
| 29 |
Biological Sciences Division at the University of Chicagobiologicalsciences.uchicago.edu
A diverse division at the University of Chicago focused on impactful research, innovative education, and comprehensive patient care |
319 |
| 30 |
Harris School of Public Policy at the University of Chicagoharris.uchicago.edu
This company focuses on critical thinking, rigorous analysis, and problem-solving to shape policy in the world, offering tools and strategies |
311 |
| 31 |
University of Illinois Chicago College of Dentistrydentistry.uic.edu
A leader in oral health education, clinical care, and research with a focus on patient-centered, evidence-based practices and a commitment to public health |
186 |
| 32 |
Soybean Innovation Labsoybeaninnovationlab.illinois.edu
The company focuses on soybean research and development in Africa to enhance agricultural productivity and reduce global poverty and hunger |
13 |
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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 Nov 2, 2026.
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The same list elsewhere in United States
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- Research institutes in Texas 57
- Research institutes in Maryland 52
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- Research institutes in Ohio 32
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