These professional services firms in Irvine largely operate in IT consulting, staffing, and environmental services. The companies listed are primarily mid-sized to large organizations. Notable firms include Allied Universal, a security and facility services provider with over 100,000 employees, and Alliant Insurance Services, an insurance brokerage founded in 1925. Salas O'Brien is an employee-owned engineering firm, while ADEC Innovations specializes in ESG data management.
The data shows a strong presence of companies founded in the 1970s and 1980s, indicating a mature business environment. Many firms, such as Trace3 and Neudesic, an IBM Company, focus on IT services, cloud solutions, and digital modernization, reflecting a significant technology services cluster within Irvine.
| # | Company | Employees | |||
|---|---|---|---|---|---|
| 1 |
Allied Universalaus.com
Provides tailored security and facility services using smart technology, supporting diverse sectors with local leadership and community presence. |
104,797 | |||
| 2 |
Alliant Insurance Servicesalliant.com
Provides innovative insurance brokerage and consulting services, supporting diverse clients with expert teams to help grow businesses and communities. |
6,616 | |||
| 3 |
Salas O'Briensalasobrien.com
Employee-owned engineering firm focused on advancing the human experience through the built environment Top-ranked, with a strong emphasis on impact and sustainability |
2,295 | |||
| 4 |
ADEC Innovationsadec-innovations.com
ADEC Innovations offers integrated industry expertise, data management, and software services to meet ESG needs, improve sustainability performance, and drive operational efficiencies globally |
1,801 | |||
| 5 |
Trace3trace3.com
Consulting on, integrating, and operating data, security, and cloud solutions to drive business transformation and create measurable value for clients |
1,440 | |||
| 6 |
JAMSjamsadr.com
JAMS provides efficient, impartial dispute resolution services globally, with industry-specific experience, top-notch facilities, and highly trained panelists for optimal outcomes |
1,097 | |||
| 7 |
Caylentcaylent.com
Cloud native services provider helping organizations optimize people and technology with AWS, enabling innovation and ambitious ideas to thrive |
899 | |||
| 8 |
Kimco Staffing Services, Inc.kimco.com
A trusted staffing agency offering office, accounting, technical, industrial, and call center placements with over 30 years of award-winning service |
857 | |||
| 9 |
Neudesic, an IBM Companyneudesic.com
Trusted technology partner specializing in digital modernization, custom application development, managed services, and business software products for impactful business results |
800 | |||
| 10 |
LPA, Inc.lpadesignstudios.com
LPA is a design firm focused on creating timeless, sustainable projects that benefit the environment, enrich human experiences, and inspire innovation |
731 | |||
| 11 |
FCSfirstcarbonsolutions.com
Leading provider of environmental, sustainability, and compliance solutions with expertise in CEQA/NEPA, compliance, permitting, natural resources management, and more Join our team! |
613 | |||
| 12 |
CyberCoderscybercoders.com
A leading recruiting firm with skilled recruiters filling thousands of positions across various industries using proprietary technology for successful placements |
608 | |||
| 13 |
Knobbe Martensknobbe.com
A highly respected intellectual property law firm with a team of 300 lawyers and scientists, serving a diverse international client base |
607 | |||
| 14 |
Hitachi Solutions Americaglobal.hitachi-solutions.com
Global IT consulting firm specializing in Microsoft platform solutions, delivering sustainable business modernization and empowering customer growth worldwide. |
589 | |||
| 15 | 582 | ||||
Want more companies than this list?This page shows the largest ones only. Connect to Tamtam to see every company that matches, filter by size, industry or growth, and reach their decision-makers. | |||||
| 16 |
Altezzasys INCaltezzasys.com
A global technology services provider offering staffing, outsourcing, consulting, and digital solutions to align technology innovation with business strategy worldwide |
571 | |||
| 17 |
Denken Solutions, Inc.denkensolutions.com
This company provides Staffing Services, SAP Solutions, and Digital Transformation Services in the IT, Engineering, and Healthcare sectors |
560 | |||
| 18 | 528 | ||||
| 19 |
The Management Trustmanagementtrust.com
A national property management firm specializing in serving condo and homeowner associations, with 100% employee ownership and a strong focus on customer service |
494 | |||
| 20 |
Renovo Solutionsrenovo1.com
Provider of Healthcare Technology Management programs offering biomedical imaging services, cybersecurity solutions, equipment maintenance cost reduction, technology management consultation, and unbiased capital equipment planning |
491 | |||
| 21 |
Triotrioadvisory.com
Global energy and sustainability advisory helping large clients transition to a net-zero future through strategy, implementation, and advanced technological solutions |
475 | |||
| 22 |
Resources Global Professionalsrgp.com
Specializing in enterprise risk management consulting to help businesses identify, assess, and mitigate risks for improved decision-making and operational success |
459 | |||
| 23 |
Strettostretto.com
Provider of comprehensive case-management, depository solutions, loan-modification services, and technology tools for legal professionals and fiduciaries in the bankruptcy industry |
408 | |||
| 24 |
Authority Partnersauthoritypartners.com
Global technology strategy consulting and custom software development company delivering digital transformation solutions to increase engagement, sales, productivity, and create value for clients |
390 | |||
| 25 |
Medical Billingaplusbillers.com
Trusted medical billing company offering personalized revenue cycle management solutions to healthcare providers, prioritizing accuracy, efficiency, and compliance |
361 | |||
| 26 |
Rutan & Tucker, LLPrutan.com
The company is a leading full-service business law firm in Orange County, representing a diverse range of clients nationwide |
348 | |||
| 27 |
Tax Relief Advocatestra.com
Specializing in tax debt relief services, we assist individuals facing wage garnishments, bank levies, audits, and other tax-related issues for financial relief |
321 | |||
| 28 |
SMA: The Program Lifecycle Companysmawins.com
SMA helps companies enhance competitiveness through consulting, program management, and technical support, guided by values of professionalism, impact, and courage |
311 | |||
| 29 |
Kahana Feldkahanafeld.com
An award-winning law firm with top litigators, proven success, client satisfaction, diverse culture, collaboration, creativity, superior results, and service |
278 | |||
| 30 |
SETA Internationalseta-international.com
Global leader in custom software development, specializing in end-to-end technology services and solutions for over 500 clients across a variety of industries worldwide |
278 | |||
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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 Nov 12, 2026.
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- SaaS companies in Irvine 50
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The same list elsewhere in United States
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