# 50 leading companies with in-house R&D in Connecticut

Tamtam tracks 101 companies with in-house R&D headquartered in Connecticut. This list ranks the 50 largest by number of employees on LinkedIn, led by Xerox, Pratt & Whitney and Stanley Black & Decker, Inc.. Their median headcount is 2,093. Half of them were founded in 1959 or later. The most common headquarters are Stamford (8), Danbury (4) and New Haven (4).

These companies with in-house R&D in Connecticut are mostly large firms across various sectors. They include established manufacturers and technology providers. For instance, Xerox offers workplace technology solutions, while Pratt & Whitney designs aircraft propulsion systems. Stanley Black & Decker provides tools and industrial systems, and HARMAN International specializes in audio products and automotive electronics. SS&C Technologies delivers cloud-based software for financial and healthcare industries, and Gartner offers expert-led research and data-driven insights. A notable pattern is the concentration of headquarters in specific cities. For example, Stamford is home to HARMAN International, Gartner, and Tronox. Norwalk hosts Xerox and Terex Corporation, and New Haven is the base for Yale University, Yale School of Medicine, and Yale New Haven Health. This indicates a clustering of research and development activities within these urban centers.

🇺🇸 Connecticut · 50 companies · Updated Nov 12, 2026

| # | Company | Industry | Headquarters | Employees | Founded |
|---|---|---|---|---|---|
| 1 | [Xerox](https://www.tamtam.ai/c/xerox) (xerox.com)<br>It provides innovative technology solutions for the workplace, focusing on print technology, software, services, and financial solutions for clients. | Business Consulting and Services | 🇺🇸 Norwalk | 47,247 |  |
| 2 | [Pratt & Whitney](https://www.tamtam.ai/c/pratt-and-whitney) (rtx.com)<br>Design and manufacture advanced propulsion systems for aircraft, enabling global connectivity, economic growth, and national defense. | Aviation and Aerospace Component Manufacturing | 🇺🇸 East Hartford | 30,378 |  |
| 3 | [Stanley Black & Decker, Inc.](https://www.tamtam.ai/c/stanley-black-and-decker-inc) (stanleyblackanddecker.com)<br>Provider of tools, fasteners, and infrastructure systems supporting home repair, automotive security, construction, and energy industries with innovation and safety. | Manufacturing | 🇺🇸 New Britain | 29,460 |  |
| 4 | [HARMAN International](https://www.tamtam.ai/c/harman-international) (harman.com)<br>Designs and manufactures premium audio products and automotive electronics, enabling smarter, safer, and immersive in-cabin vehicle experiences worldwide. | Computers and Electronics Manufacturing | 🇺🇸 Stamford | 27,936 | 1980 |
| 5 | [SS&C Technologies](https://www.tamtam.ai/c/ss-and-c-technologies) (ssctech.com)<br>Provider of cloud-based software and solutions for financial and healthcare industries, serving over 22,000 companies globally. | Software Development | 🇺🇸 Windsor | 27,478 | 1986 |
| 6 | [Gartner](https://www.tamtam.ai/c/gartner) (gartner.com)<br>A global company providing expert-led research and data-driven insights to help executives make faster, smarter decisions and achieve stronger performance | Information Services | 🇺🇸 Stamford | 22,206 | 1979 |
| 7 | [Yale University](https://www.tamtam.ai/c/yale-university) (news.yale.edu)<br>Research university fostering global connections, creativity, and innovation, emphasizing student learning and positive worldwide impact. | Higher Education | 🇺🇸 New Haven | 19,675 |  |
| 8 | [General Dynamics Electric Boat](https://www.tamtam.ai/c/general-dynamics-electric-boat) (gdeb.com)<br>Design and build nuclear-powered submarines for the U.S. Navy, including Virginia-class and Columbia-class ballistic missile submarines. | Defense and Space Manufacturing | 🇺🇸 Groton | 9,481 | 1899 |
| 9 | [Terex Corporation](https://www.tamtam.ai/c/terex-corporation) (terex.com)<br>A global manufacturing company focused on building essential machines, improving lives, volunteering, and maintaining a safe, inclusive work environment | Machinery Manufacturing | 🇺🇸 Norwalk | 8,109 | 1933 |
| 10 | [Yale School of Medicine](https://www.tamtam.ai/c/yale-school-of-medicine) (medicine.yale.edu)<br>A world-renowned center for biomedical research, education, and advanced healthcare with affiliations to leading institutions and a unique curriculum promoting independent thinking | Research Services | 🇺🇸 New Haven | 6,960 |  |
| 11 | [Praxair, Inc - a Linde Company](https://www.tamtam.ai/c/praxair-inc-a-linde-company) (lindeus.com)<br>A global leader in industrial gases and engineering, providing high-quality gases, technologies, and services to diverse markets while promoting sustainability and productivity | Chemical Manufacturing | 🇺🇸 Danbury | 6,549 |  |
| 12 | [PerkinElmer](https://www.tamtam.ai/c/perkinelmer) (perkinelmer.com)<br>A global provider of technology and service solutions for measuring, quantifying, detecting, and reporting in various industries to ensure quality and safety | Biotechnology Research | 🇺🇸 Shelton | 6,485 | 1937 |
| 13 | [Tronox](https://www.tamtam.ai/c/tronox) (tronox.com)<br>A global producer of titanium dioxide and inorganic chemicals, specializing in mining, processing, and manufacturing products for various industries worldwide | Chemical Manufacturing | 🇺🇸 Stamford | 5,877 | 2012 |
| 14 | [Sikorsky](https://www.tamtam.ai/c/sikorsky) (lockheedmartin.com)<br>A global leader in helicopter technology, providing innovative and safe flight solutions for commercial and military markets worldwide since 1939 | Aviation and Aerospace Component Manufacturing | 🇺🇸 Stratford | 5,753 | 1923 |
| 15 | [Yale New Haven Health](https://www.tamtam.ai/c/yale-new-haven-health) (ynhhs.org)<br>A healthcare organization with five hospitals offering advanced medical treatments, research, and innovations, along with access to primary care physicians and specialists | Hospitals and Health Care | 🇺🇸 New Haven | 5,708 | 1996 |
| 16 | [Amphenol](https://www.tamtam.ai/c/amphenol) (amphenol.com)<br>A Fortune 500 manufacturer with 90,000 employees worldwide, providing key components for electronic devices and networks in daily use | Appliances, Electrical, and Electronics Manufacturing | 🇺🇸 Wallingford | 5,559 |  |
| 17 | [Crane Company](https://www.tamtam.ai/c/crane-company) (craneco.com)<br>Long-standing ethical business focused on innovation, disciplined management, strategic acquisitions, and creating value for customers, suppliers, and shareholders. | Manufacturing | 🇺🇸 Stamford | 4,696 | 1855 |
| 18 | [IMS Health](https://www.tamtam.ai/c/ims-health) (iqvia.com)<br>Provides healthcare data, analytics, and technology solutions to improve clinical, commercial, and real-world outcomes in the life sciences industry. | Hospitals and Health Care | 🇺🇸 Danbury | 4,675 | 1954 |
| 19 | [Interactive Brokers](https://www.tamtam.ai/c/interactive-brokers) (interactivebrokers.com)<br>Provides automated trade execution and custody for diverse financial instruments across global markets, offering advanced tools and research at low cost. | Financial Services | 🇺🇸 Greenwich | 3,506 |  |
| 20 | [Hexcel Corporation](https://www.tamtam.ai/c/hexcel-corporation) (hexcel.com)<br>Production of carbon fiber reinforcements, resin systems, and honeycomb materials focused on lightweight solutions for commercial aerospace industry. | Aviation and Aerospace Component Manufacturing | 🇺🇸 Stamford | 3,357 | 1948 |
| 21 | [Edgewell Personal Care](https://www.tamtam.ai/c/edgewell-personal-care) (edgewell.com)<br>Global personal care company with 25+ brands, serving 50+ countries, focusing on efficiency, sustainability, and inclusive workplace culture. | Personal Care Product Manufacturing | 🇺🇸 Shelton | 3,354 | 2015 |
| 22 | [Amphenol Communications Solutions](https://www.tamtam.ai/c/amphenol-communications-solutions) (amphenol-cs.com)<br>Design and manufacture innovative connectors and cable assemblies for communications, mobile, RF, optics, data centers, networking, industrial, and automotive applications. | Appliances, Electrical, and Electronics Manufacturing | 🇺🇸 United States | 3,169 | 1932 |
| 23 | [Southern Connecticut State University](https://www.tamtam.ai/c/southern-connecticut-state-university) (southernct.edu)<br>This institution offers diverse, quality graduate and undergraduate education in liberal arts and professional disciplines, emphasizing academic excellence, social justice, and public service | Higher Education | 🇺🇸 New Haven | 2,666 | 1893 |
| 24 | [Connecticut Children's](https://www.tamtam.ai/c/connecticut-children-s) (connecticutchildrens.org)<br>A leading pediatric academic medical center dedicated to advancing pediatric care through medical innovation, technology, research, and specialized healthcare services | Hospitals and Health Care | 🇺🇸 Hartford | 2,621 | 1996 |
| 25 | [Conair LLC](https://www.tamtam.ai/c/conair-llc) (conair.com)<br>Design and manufacture of personal care, kitchen appliances, cookware, hair accessories, cosmetic and travel products sold globally. | Manufacturing | 🇺🇸 Stamford | 2,093 | 1959 |
| 26 | [Cristal](https://www.tamtam.ai/c/cristal) (tronox.com)<br>A leading producer of titanium dioxide and zircon products, with a global footprint in mining, processing, and sale of mineral sands | Chemical Manufacturing | 🇺🇸 Stamford | 2,050 |  |
| 27 | [Hamilton Sundstrand](https://www.tamtam.ai/c/hamilton-sundstrand) (hamiltonsundstrand.com)<br>A global supplier of aerospace and industrial products, designing and manufacturing systems for aircraft and international space programs | Aviation and Aerospace Component Manufacturing | 🇺🇸 Windsor Locks | 1,918 |  |
| 28 | [CooperSurgical](https://www.tamtam.ai/c/coopersurgical) (coopersurgical.com)<br>This company is focused on advancing women's, babies', and families' healthcare worldwide through products and services for reproductive solutions and gynecological care | Medical Equipment Manufacturing | 🇺🇸 Trumbull | 1,845 | 1990 |
| 29 | [Timex Group](https://www.tamtam.ai/c/timex-group) (timexgroup.com)<br>Design, manufacture, and market innovative watches globally under multiple renowned brands, employing over 3,000 people worldwide. | Manufacturing | 🇺🇸 Middlebury | 1,624 | 1854 |
| 30 | [Linde Gas & Equipment](https://www.tamtam.ai/c/linde-gas-and-equipment) (lindedirect.com)<br>A trusted provider of industrial gases, welding supplies, cutting machines, and automation, offering solutions to reduce costs and increase productivity | Chemical Manufacturing | 🇺🇸 Danbury | 1,552 |  |
| 31 | [GeneDx](https://www.tamtam.ai/c/genedx) (genedx.com)<br>Specializing in genetic diagnosis, offering exome and genome tests to provide personalized health plans, accelerate drug discovery, and improve health system efficiencies | Biotechnology Research | 🇺🇸 Stamford | 1,260 |  |
| 32 | [Aurobindo Pharma USA, Inc.](https://www.tamtam.ai/c/aurobindo-pharma-usa-inc) (aurobindousa.com)<br>Provider of affordable generic pharmaceuticals with a broad portfolio of over 150 product families across various therapeutic categories Recognized for rapid growth and high prescription dispensing | Pharmaceutical Manufacturing | 🇺🇸 East Windsor | 1,198 | 1994 |
| 33 | [RBC Bearings](https://www.tamtam.ai/c/rbc-bearings) (rbcbearings.com)<br>International manufacturer of precision bearings, specializing in highly technical and regulated products for industrial, aerospace, and defense markets Offers unique design solutions and exceptional quality | Aviation and Aerospace Component Manufacturing | 🇺🇸 Oxford | 1,106 | 1919 |
| 34 | [TRUMPF North America](https://www.tamtam.ai/c/trumpf-north-america) (trumpf.com)<br>Leading provider of sheet metal fabrication machinery and industrial lasers, focusing on innovative, networked manufacturing solutions in North America. | Machinery Manufacturing | 🇺🇸 Farmington | 987 | 1969 |
| 35 | [MacDermid Enthone Industrial Solutions](https://www.tamtam.ai/c/macdermid-enthone-industrial-solutions) (macdermidenthone.com)<br>Global leader in manufacturing chemical compounds for surface coating applications, offering innovative solutions, sustainable technologies, and technical support to meet customer needs | Chemical Manufacturing | 🇺🇸 Waterbury | 961 | 1922 |
| 36 | [AQR Capital Management](https://www.tamtam.ai/c/aqr-capital-management) (aqr.com)<br>Global investment management firm combining economics, behavioral finance, data, and technology to optimize client portfolio performance worldwide. | Financial Services | 🇺🇸 Greenwich | 957 | 1998 |
| 37 | [United States Department of the Air Force](https://www.tamtam.ai/c/united-states-department-of-the-air-force) (af.mil)<br>This company is one of the three Military Departments in the US Department of Defense, encompassing the USAF and USSF | Military | 🇺🇸 Washington | 840 | 1947 |
| 38 | [MannKind Corporation](https://www.tamtam.ai/c/mannkind-corporation) (mannkindcorp.com)<br>This company focuses on developing and commercializing therapeutic products and devices for endocrine and orphan lung diseases, aiming to improve patients' lives | Pharmaceutical Manufacturing | 🇺🇸 Danbury | 833 | 1991 |
| 39 | [Dorel Sports](https://www.tamtam.ai/c/dorel-sports) (privacy.ponbike.com)<br>A global company within Dorel Industries, committed to helping consumers find their perfect ride through innovative cycling products in over 100 countries | Consumer Goods | 🇺🇸 Wilton | 825 |  |
| 40 | [Mastercam](https://www.tamtam.ai/c/mastercam) (mastercam.com)<br>Develops and supplies advanced CAD/CAM software for diverse manufacturing processes, enabling precision, productivity, and performance for various industries globally. | Software Development | 🇺🇸 Tolland | 809 | 1983 |
| 41 | [Ensign-Bickford Aerospace & Defense Company (EBAD)](https://www.tamtam.ai/c/ensign-bickford-aerospace-and-defense-company-ebad) (ebad.com)<br>Global leader in precision energetics systems and explosive solutions, offering customized hardware and systems solutions for aerospace and defense missions worldwide | Defense and Space Manufacturing | 🇺🇸 Simsbury | 734 | 1836 |
| 42 | [LATICRETE International](https://www.tamtam.ai/c/laticrete-international) (eu.laticrete.com)<br>Manufactures construction solutions: tile, masonry, flooring finishes, concrete chemicals, restoration systems; offers sustainable products for LEED certification with strong warranties. | Wholesale Building Materials | 🇺🇸 Bethany (New Haven) | 694 | 1956 |
| 43 | [MacDermid Performance Solutions](https://www.tamtam.ai/c/macdermid-performance-solutions) (macdermid.com)<br>Manufacture specialty chemicals and materials for electronics, printing, plating, and offshore oil industries using advanced technological processes. | Chemical Manufacturing | 🇺🇸 Waterbury | 622 |  |
| 44 | [Cannondale](https://www.tamtam.ai/c/cannondale) (cannondale.com)<br>Innovative bicycle company since 1971, focused on inspiring the world to ride and improving cycling through relentless innovation and global reach | Sporting Goods Manufacturing | 🇺🇸 Wilton | 611 | 1971 |
| 45 | [The Lee Company](https://www.tamtam.ai/c/the-lee-company) (theleeco.com)<br>A pioneer in miniature precision fluid control components for various industries, specializing in miniaturization and engineering expertise for cutting-edge fluid flow technology | Industrial Machinery Manufacturing | 🇺🇸 Westbrook | 588 | 1948 |
| 46 | [CooperSurgical Fertility Solutions](https://www.tamtam.ai/c/coopersurgical-fertility-solutions) (coopersurgical.com)<br>Global leader in IVF and reproductive genetics, providing innovative products and services for every step in the assisted reproductive technology journey. | Medical Equipment Manufacturing | 🇺🇸 Trumbull | 578 | 2018 |
| 47 | [GameChange Energy](https://www.tamtam.ai/c/gamechange-energy) (gamechangeenergy.com)<br>A manufacturer of solar racking systems, GameChange Solar offers fast installation, bankable quality, and high value through superior engineering and design | Renewable Energy Semiconductor Manufacturing | 🇺🇸 Norwalk | 542 | 2012 |
| 48 | [Davis-Standard](https://www.tamtam.ai/c/davis-standard) (davis-standard.com)<br>Global leader in extrusion and converting technology, offering innovative solutions across multiple industries with a focus on efficiency and sustainability | Machinery Manufacturing | 🇺🇸 Pawcatuck | 538 | 1848 |
| 49 | [Gerber Technology, a Lectra Company](https://www.tamtam.ai/c/gerber-technology-a-lectra-company) (lectra.com)<br>A global provider of software and automation solutions in fashion, automotive, and furniture industries, with a focus on innovation and technology | IT Services and IT Consulting | 🇺🇸 Tolland | 522 |  |
| 50 | [Zygo](https://www.tamtam.ai/c/zygo) (zygo.com)<br>Global leader in designing and manufacturing advanced optical metrology systems, ultra-precise optical components, and assemblies for various industries worldwide | Measuring and Control Instrument Manufacturing | 🇺🇸 Middlefield | 513 | 1970 |

## 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 Nov 12, 2026.

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- [Companies with in-house R&D in the world](https://www.tamtam.ai/l/r-and-d-companies-in-the-world) (34,346)
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Source: https://www.tamtam.ai/l/r-and-d-companies-connecticut