Tamtam Start free

Professional services firms headquartered in Irvine

Tamtam tracks 61 professional services firms headquartered in Irvine. This list ranks the 30 largest by number of employees on LinkedIn, led by Allied Universal, Alliant Insurance Services and Salas O'Brien. Their median headcount is 582. Half of them were founded in 1999 or later.

馃嚭馃嚫 Irvine30 companiesUpdated Nov 12, 2026

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.

#CompanyIndustryHeadquarters EmployeesFounded
1
Allied Universalaus.com

Provides tailored security and facility services using smart technology, supporting diverse sectors with local leadership and community presence.

Professional Services 馃嚭馃嚫 Irvine 104,797 n/a
2
Alliant Insurance Servicesalliant.com

Provides innovative insurance brokerage and consulting services, supporting diverse clients with expert teams to help grow businesses and communities.

Insurance Agencies and Brokerages 馃嚭馃嚫 Irvine 6,616 1925
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

Engineering Services 馃嚭馃嚫 Irvine 2,295 1975
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

Business Consulting and Services 馃嚭馃嚫 Irvine 1,801 n/a
5
Trace3trace3.com

Consulting on, integrating, and operating data, security, and cloud solutions to drive business transformation and create measurable value for clients

IT Services and IT Consulting 馃嚭馃嚫 Irvine 1,440 2002
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

Alternative Dispute Resolution 馃嚭馃嚫 Irvine 1,097 1979
7
Caylentcaylent.com

Cloud native services provider helping organizations optimize people and technology with AWS, enabling innovation and ambitious ideas to thrive

IT Services and IT Consulting 馃嚭馃嚫 Irvine 899 2015
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

Staffing and Recruiting 馃嚭馃嚫 Irvine 857 1986
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

IT Services and IT Consulting 馃嚭馃嚫 Irvine 800 2002
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

Architecture and Planning 馃嚭馃嚫 Irvine 731 1965
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!

Environmental Services 馃嚭馃嚫 Irvine 613 1982
12
CyberCoderscybercoders.com

A leading recruiting firm with skilled recruiters filling thousands of positions across various industries using proprietary technology for successful placements

Staffing and Recruiting 馃嚭馃嚫 Irvine 608 1999
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

Law Practice 馃嚭馃嚫 Irvine 607 1962
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.

IT Services and IT Consulting 馃嚭馃嚫 Irvine 589 1971
15
LSAlsa.net

A diversified environmental, transportation, and community planning firm offering expert services in various fields, operating across nine California offices

Environmental Services 馃嚭馃嚫 Irvine 582 1976

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.

Get more companies, free
16
Altezzasys INCaltezzasys.com

A global technology services provider offering staffing, outsourcing, consulting, and digital solutions to align technology innovation with business strategy worldwide

IT Services and IT Consulting 馃嚭馃嚫 Irvine 571 2014
17
Denken Solutions, Inc.denkensolutions.com

This company provides Staffing Services, SAP Solutions, and Digital Transformation Services in the IT, Engineering, and Healthcare sectors

Staffing and Recruiting 馃嚭馃嚫 Irvine 560 2010
18
KTGYktgy.com

Award-winning design firm specializing in architecture, branding, interiors, and planning, dedicated to innovation, creativity, and making a positive impact on communities

Architecture and Planning 馃嚭馃嚫 Irvine 528 n/a
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

Real Estate 馃嚭馃嚫 Irvine 494 2005
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

Hospitals and Health Care 馃嚭馃嚫 Irvine 491 2009
21
Triotrioadvisory.com

Global energy and sustainability advisory helping large clients transition to a net-zero future through strategy, implementation, and advanced technological solutions

Business Consulting and Services 馃嚭馃嚫 Irvine 475 2013
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

Business Consulting and Services 馃嚭馃嚫 Irvine 459 1996
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

Business Consulting and Services 馃嚭馃嚫 Irvine 408 1987
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

IT Services and IT Consulting 馃嚭馃嚫 Irvine 390 1998
25
Medical Billingaplusbillers.com

Trusted medical billing company offering personalized revenue cycle management solutions to healthcare providers, prioritizing accuracy, efficiency, and compliance

Business Consulting and Services 馃嚭馃嚫 Irvine 361 2006
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

Law Practice 馃嚭馃嚫 Irvine 348 n/a
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

Accounting 馃嚭馃嚫 Irvine 321 2017
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

Professional Services 馃嚭馃嚫 Irvine 311 1982
29
Kahana Feldkahanafeld.com

An award-winning law firm with top litigators, proven success, client satisfaction, diverse culture, collaboration, creativity, superior results, and service

Law Practice 馃嚭馃嚫 Irvine 278 2017
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

IT Services and IT Consulting 馃嚭馃嚫 Irvine 278 2008

Turn this list into pipeline

Tamtam finds the decision-makers at every company on a list like this one, with verified emails, phone numbers and the buying signals that tell you when to reach out.

Build your own list, free

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.

More company lists in Irvine

The same list elsewhere in United States

The same list elsewhere