# 39 leading professional services firms in Oklahoma
Tamtam tracks 39 professional services firms headquartered in Oklahoma. This list ranks all of them by number of employees on LinkedIn, led by Express Employment International, Chickasaw Nation Industries, Inc. and Cypress Environmental Partners. Their median headcount is 306. Half of them were founded in 2000 or later. The most common headquarters are Tulsa (16) and Oklahoma City (13).
These professional services firms in Oklahoma include a mix of large enterprises and mid-sized companies, with a notable presence in staffing, IT services, and the oil and gas sector. Express Employment International, for example, is an international staffing company. Chickasaw Nation Industries, Inc. operates subsidiaries for government and commercial clients. Cypress Environmental Partners provides environmental services for energy and infrastructure, while DNI (Delaware Nation Industries) is a parent organization for IT businesses. Tulsa Inspection Resources, LLC offers inspection services for energy and civil industries.
A clear pattern among these companies is the strong concentration in the oil and gas industry, reflecting Oklahoma's economic landscape. Many of these firms, such as Tulsa Inspection Resources and Frontier Integrity Solutions, provide specialized inspection, integrity, and environmental services directly supporting the energy sector. Another observation is the prevalence of companies headquartered in Tulsa and Oklahoma City.
๐บ๐ธ Oklahoma ยท 39 companies ยท Updated Nov 11, 2026
| # | Company | Industry | Headquarters | Employees | Founded |
|---|---|---|---|---|---|
| 1 | [Express Employment International](https://www.tamtam.ai/c/express-employment-international) (expresspros.com)
International staffing company supporting franchise locations worldwide, providing staffing and HR services to connect individuals with jobs and businesses with employees | Staffing and Recruiting | ๐บ๐ธ Oklahoma City | 14,211 | 1983 |
| 2 | [Chickasaw Nation Industries, Inc.](https://www.tamtam.ai/c/chickasaw-nation-industries-inc) (chickasaw.com)
Operating subsidiaries for federal government and commercial clients, offering solutions in various sectors, supporting Chickasaw Nation economic development. | Government Relations Services | ๐บ๐ธ Norman | 1,095 | 1996 |
| 3 | [Cypress Environmental Partners](https://www.tamtam.ai/c/cypress-environmental-partners) (tirusa.com)
Nationally recognized environmental services company offering inspection, integrity, and water treatment solutions to support energy, water, and civil infrastructure sectors in the US | Oil and Gas | ๐บ๐ธ Tulsa | 963 | 2003 |
| 4 | [AHS Staffing](https://www.tamtam.ai/c/ahs-staffing) (ahsstaffing.com)
Connecting healthcare providers with top talent for employment opportunities with passion, loyalty, and integrity to benefit employees, clients, and community | Staffing and Recruiting | ๐บ๐ธ Edmond | 869 | 2008 |
| 5 | [Tulsa Inspection Resources, LLC](https://www.tamtam.ai/c/tulsa-inspection-resources-llc) (tirusa.com)
This company offers inspection services, non-destructive examination, and pipeline integrity support to energy, civil, and municipal water industries in the US | Oil and Gas | ๐บ๐ธ Tulsa | 866 | 2003 |
| 6 | [DNI (Delaware Nation Industries)](https://www.tamtam.ai/c/dni-delaware-nation-industries) (dnigov.com)
A parent organization for IT businesses owned by Delaware Nation, offering a suite of services and capabilities through strategic acquisitions and partnerships | IT Services and IT Consulting | ๐บ๐ธ Oklahoma City | 775 | 2015 |
| 7 | [GDH](https://www.tamtam.ai/c/gdh) (bit.ly)
Technology workforce solutions provider offering staffing, project solutions, and recruitment process outsourcing, dedicated to delivering top talent, support, and service | IT Services and IT Consulting | ๐บ๐ธ Tulsa | 742 | 2001 |
| 8 | [Quality Integrated Services, Inc. (QIS)](https://www.tamtam.ai/c/quality-integrated-services-inc-qis) (qisinspection.com)
Industry leader in inspection and construction management services with over 25 years of experience, prioritizing safety, employee retention, and customer satisfaction | Oil and Gas | ๐บ๐ธ Guymon | 650 | 1991 |
| 9 | [HoganTaylor](https://www.tamtam.ai/c/hogantaylor) (hogantaylor.com)
Professional business advisors offering comprehensive advisory, tax, accounting, assurance, human capital, and technology solutions with personal attention and commitment to success | Accounting | ๐บ๐ธ Tulsa | 411 | |
| 10 | [capSpire](https://www.tamtam.ai/c/capspire) (capspire.com)
Experts in driving growth throughout the value chain through consulting, process implementation, operational support, and industry knowledge for strategic business advancement | IT Services and IT Consulting | ๐บ๐ธ Tulsa | 408 | 2009 |
| 11 | [McAfee & Taft](https://www.tamtam.ai/c/mcafee-and-taft) (mcafeetaft.com)
A leading Oklahoma-based law firm providing comprehensive legal solutions in various practice areas with a focus on creative strategies and client representation | Law Practice | ๐บ๐ธ Oklahoma City | 405 | 1952 |
| 12 | [Frontier Integrity Solutions](https://www.tamtam.ai/c/frontier-integrity-solutions) (frontierintegrity.com)
A strategic inspection provider offering progressive Inspector development, prioritizing retention and cost sensitivity, providing value-added services with integrity and commitment 24/7 | Oil and Gas | ๐บ๐ธ Tulsa | 392 | 1975 |
| 13 | [CECยฎ](https://www.tamtam.ai/c/cec-oklahoma-city) (connectcec.com)
The company is a privately-held engineering firm offering a wide range of services including transportation design, power delivery, construction management, and environmental services | Civil Engineering | ๐บ๐ธ Oklahoma City | 392 | 1966 |
| 14 | [Universal Field Services, Inc.](https://www.tamtam.ai/c/universal-field-services-inc) (ufsrw.com)
A leader in land acquisition services, offering negotiations, permitting, project management, and more with a focus on client success and quality processes | Real Estate | ๐บ๐ธ Tulsa | 361 | 1958 |
| 15 | [Express Personnel Services](https://www.tamtam.ai/c/express-personnel-services) (expresspros.com)
Connecting job seekers with top local employers, providing recruitment and hiring assistance for administrative, commercial, and professional roles across various industries and skill levels. | Human Resources Services | ๐บ๐ธ Enid | 328 | |
| 16 | [Robinson Aviation (RVA), Inc.](https://www.tamtam.ai/c/robinson-aviation-rva-inc) (rvainc.com)
An aviation services company specializing in air traffic control operations, communications systems engineering, aviation safety studies, and transportation security planning | Airlines and Aviation | ๐บ๐ธ Oklahoma City | 327 | 1986 |
| 17 | [American Piping Inspection](https://www.tamtam.ai/c/american-piping-inspection) (americanpipinginspection.com)
Established in 2006, this company offers NDE/NDT, Level III services, welder certification, 3rd party inspection, and construction services in multiple states | Oil and Gas | ๐บ๐ธ Tulsa | 325 | 2006 |
| 18 | [OakTree Staffing](https://www.tamtam.ai/c/oaktree-staffing) (oaktreestaffing.com)
A company helping job seekers connect with top corporations and find success in diverse career opportunities for over 25 years | Staffing and Recruiting | ๐บ๐ธ Tulsa | 322 | 1995 |
| 19 | [Wallace Design Collective](https://www.tamtam.ai/c/wallace-design-collective) (wallace.design)
A multidisciplinary design company offering civil and structural engineering, landscape architecture, land planning, and specialized inspections with a focus on improving lives | Design Services | ๐บ๐ธ Tulsa | 318 | 1981 |
| 20 | [InterWorks](https://www.tamtam.ai/c/interworks) (interworks.com)
A people-focused tech consultancy offering premier services in data management, visualization, server monitoring, and IT solutions tailored to unique client needs | IT Services and IT Consulting | ๐บ๐ธ Stillwater | 306 | 1996 |
| 21 | [Inceed](https://www.tamtam.ai/c/inceed) (inceed.com)
A top-tier staffing company specializing in IT and Finance, dedicated to matching top talent with Fortune 500 companies and small businesses | Staffing and Recruiting | ๐บ๐ธ Tulsa | 185 | 2001 |
| 22 | [McDaniel Technical Services, Inc.](https://www.tamtam.ai/c/mcdaniel-technical-services-inc) (mcdanieltsi.com)
The company provides construction management, third party inspection, project support, and staffing services for oil and natural gas pipelines and related facilities nationwide | Oil and Gas | ๐บ๐ธ Broken Arrow | 184 | 2000 |
| 23 | [Aviation Training Consulting](https://www.tamtam.ai/c/aviation-training-consulting) (atc-hq.com)
Aviation Training Consulting provides agile solutions for government and private-sector organizations, leveraging institutional expertise and industry experts for mission-critical operations | Defense and Space Manufacturing | ๐บ๐ธ Altus | 183 | 2001 |
| 24 | [Finley & Cook PLLC](https://www.tamtam.ai/c/finley-and-cook-pllc) (finley-cook.com)
A full-service accounting firm founded in 1947, providing nationwide customized accounting, audit, consulting, and tax services with over 75 years of experience and innovation | Accounting | ๐บ๐ธ Shawnee | 183 | 1947 |
| 25 | [Cyntergy_](https://www.tamtam.ai/c/cyntergy) (cyntergy.com)
A full service Architecture, Engineering, and Construction Administration firm with a focus on successful client relationships, communication, and creative design solutions | Architecture and Planning | ๐บ๐ธ Tulsa | 182 | 1997 |
| 26 | [KeyBridge Technologies, Inc](https://www.tamtam.ai/c/keybridge-technologies-inc) (keybridgeti.com)
Innovative business solutions provider optimizing assets, knowledge, and service with a dedicated staff and proven track record for customer satisfaction | IT Services and IT Consulting | ๐บ๐ธ Oklahoma City | 147 | |
| 27 | [Novus Consulting](https://www.tamtam.ai/c/novus-consulting) (novusconsulting.com)
Novus Consulting provides comprehensive strategies and transformation management for clients, addressing complex issues around people, process, technology, and data | IT Services and IT Consulting | ๐บ๐ธ Oklahoma City | 69 | 2020 |
| 28 | [Basin Engineering](https://www.tamtam.ai/c/basin-engineering) (basinengineering.com)
Energy engineering and operations consulting firm specializing in drilling, completion, production operations, and petroleum engineering for oil and gas companies worldwide | Oil and Gas | ๐บ๐ธ Oklahoma City | 46 | 1995 |
| 29 | [GSB, Inc.](https://www.tamtam.ai/c/gsb-inc) (gsb-inc.com)
A seasoned architecture firm with a national scope, specializing in sustainable design for various projects including resorts, education facilities, and residential developments | Architecture and Planning | ๐บ๐ธ Oklahoma City | 40 | 1979 |
| 30 | [Karsten Group](https://www.tamtam.ai/c/karsten-group) (karstenhrgroup.com)
Certified HR and payroll professionals offering a comprehensive solution for managing employees, bridging HR administration with business operations | Human Resources Services | ๐บ๐ธ Oklahoma City | 36 | 2017 |
| 31 | [McCoy & Orta, a Professional Corporation](https://www.tamtam.ai/c/mccoy-and-orta-a-professional-corporation) (mccoy-orta.com)
Nationally-recognized law firm specializing in commercial loan originations, servicing, mortgage transfers, and representing private equity firms in the CMBS industry | Legal Services | ๐บ๐ธ Oklahoma City | 33 | 1992 |
| 32 | [VoiceFoundry](https://www.tamtam.ai/c/voicefoundry) (ttecdigital.com)
Provider of AWS-powered digital transformation and consulting services, specializing in creating exceptional customer experiences and maximizing complex technology ecosystems | IT Services and IT Consulting | ๐บ๐ธ Tulsa | 26 | |
| 33 | [Johnson & Jones, P.C.](https://www.tamtam.ai/c/johnson-and-jones-p-c) (johnson-jones.com)
Established in 1994, the Firm offers expertise in business law, litigation, and estate planning, serving clients in various legal matters with community involvement | Law Practice | ๐บ๐ธ Tulsa | 12 | 1994 |
| 34 | [Psychology Specialists of Oklahoma, PLLC](https://www.tamtam.ai/c/psychology-specialists-of-oklahoma-pllc) (psychologyoklahoma.com)
A behavioral health group practice in Oklahoma City specializing in psychological and neuropsychological evaluations and assessments to meet community needs | Mental Health Care | ๐บ๐ธ Oklahoma City | 11 | 2006 |
| 35 | [Cognitionteam](https://www.tamtam.ai/c/cognitionteam) (cognitionteam.com)
A professional services firm specializing in digital, cloud, and cyber security services, offering design and development of web and mobile applications, and enterprise-scale software solutions | IT Services and IT Consulting | ๐บ๐ธ Oklahoma City | 7 | 2018 |
| 36 | [Ball Morse Lowe PLLC](https://www.tamtam.ai/c/ball-morse-lowe-pllc) (bml.law)
Full-service law firm specializing in family law, oil and gas, real property, business transactions, commercial litigation, and probate and estate planning across multiple states | Legal Services | ๐บ๐ธ Edmond | 4 | 2008 |
| 37 | [Lone Cypress Energy Services, LLC.](https://www.tamtam.ai/c/lone-cypress-energy-services-llc) (lonecypressenergyservices.com)
Independent energy company in Tulsa, OK specializing in traditional and renewable infrastructure development, EPC contracting, project management, and system operations for accessible and sustainable energy solutions | Oil and Gas | ๐บ๐ธ Tulsa | 4 | 2017 |
| 38 | [Lawless Consulting - Getting to Market faster!](https://www.tamtam.ai/c/lawless-consulting-getting-to-market-faster) (lawless-consulting.com)
Specializes in Knowledge Driven Product Development for medical devices, offering engineering resources and expertise to fast-track products from idea to commercialization | Business Consulting and Services | ๐บ๐ธ Locust Grove | 3 | 2011 |
| 39 | [ERP Associates](https://www.tamtam.ai/c/erp-associates) (erpassociates.com)
Specializing in transforming back-office systems, this company helps fortune 500 clients scale PMO and Architecture capabilities for business transformation and technology modernization projects Connect today | IT Services and IT Consulting | ๐บ๐ธ Tulsa | 2 | 2004 |
## 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 11, 2026.
## More company lists in Oklahoma
- [The largest companies in Oklahoma](https://www.tamtam.ai/l/largest-companies-oklahoma) (714)
- [Oil and Gas companies in Oklahoma](https://www.tamtam.ai/l/oil-and-gas-companies-oklahoma) (112)
- [Energy companies in Oklahoma](https://www.tamtam.ai/l/energy-companies-oklahoma) (103)
- [Critical infrastructure operators in Oklahoma](https://www.tamtam.ai/l/critical-infrastructure-operators-oklahoma) (86)
- [Retail chains in Oklahoma](https://www.tamtam.ai/l/retail-chains-oklahoma) (73)
- [Education providers in Oklahoma](https://www.tamtam.ai/l/education-companies-oklahoma) (70)
- [Healthcare providers in Oklahoma](https://www.tamtam.ai/l/healthcare-providers-oklahoma) (57)
- [Manufacturers in Oklahoma](https://www.tamtam.ai/l/manufacturers-oklahoma) (55)
- [Public sector organisations in Oklahoma](https://www.tamtam.ai/l/public-sector-organisations-oklahoma) (53)
- [Financial services firms in Oklahoma](https://www.tamtam.ai/l/financial-services-firms-oklahoma) (51)
- [Multinational companies in Oklahoma](https://www.tamtam.ai/l/multinational-companies-oklahoma) (51)
- [Hospitals and Health Care companies in Oklahoma](https://www.tamtam.ai/l/hospitals-and-health-care-companies-oklahoma) (44)
- [Companies with a mobile app in Oklahoma](https://www.tamtam.ai/l/companies-with-mobile-app-oklahoma) (41)
- [Hardware manufacturers in Oklahoma](https://www.tamtam.ai/l/hardware-companies-oklahoma) (40)
- [Companies with in-house R&D in Oklahoma](https://www.tamtam.ai/l/r-and-d-companies-oklahoma) (40)
- [Higher Education companies in Oklahoma](https://www.tamtam.ai/l/higher-education-companies-oklahoma) (35)
- [Family-owned companies in Oklahoma](https://www.tamtam.ai/l/family-owned-companies-oklahoma) (32)
- [Hotel and hospitality groups in Oklahoma](https://www.tamtam.ai/l/hospitality-groups-oklahoma) (30)
- [Government Administration companies in Oklahoma](https://www.tamtam.ai/l/government-administration-companies-oklahoma) (25)
- [Publicly traded companies in Oklahoma](https://www.tamtam.ai/l/publicly-traded-companies-oklahoma) (25)
## The same list elsewhere in United States
- [Professional services firms in the United States](https://www.tamtam.ai/l/professional-services-firms-united-states) (7,078)
- [Professional services firms in New York State](https://www.tamtam.ai/l/professional-services-firms-new-york-state) (955)
- [Professional services firms in California](https://www.tamtam.ai/l/professional-services-firms-california) (880)
- [Professional services firms in Texas](https://www.tamtam.ai/l/professional-services-firms-texas) (629)
- [Professional services firms in Florida](https://www.tamtam.ai/l/professional-services-firms-florida) (375)
- [Professional services firms in Virginia](https://www.tamtam.ai/l/professional-services-firms-virginia) (344)
- [Professional services firms in Illinois](https://www.tamtam.ai/l/professional-services-firms-illinois) (339)
- [Professional services firms in Massachusetts](https://www.tamtam.ai/l/professional-services-firms-massachusetts) (249)
- [Professional services firms in New Jersey](https://www.tamtam.ai/l/professional-services-firms-new-jersey) (249)
- [Professional services firms in Georgia](https://www.tamtam.ai/l/professional-services-firms-georgia) (246)
- [Professional services firms in Pennsylvania](https://www.tamtam.ai/l/professional-services-firms-pennsylvania) (245)
- [Professional services firms in Ohio](https://www.tamtam.ai/l/professional-services-firms-ohio) (195)
- [Professional services firms in Maryland](https://www.tamtam.ai/l/professional-services-firms-maryland) (176)
- [Professional services firms in Michigan](https://www.tamtam.ai/l/professional-services-firms-michigan) (172)
- [Professional services firms in Washington State](https://www.tamtam.ai/l/professional-services-firms-washington-state) (163)
- [Professional services firms in North Carolina](https://www.tamtam.ai/l/professional-services-firms-north-carolina) (142)
- [Professional services firms in Alabama](https://www.tamtam.ai/l/professional-services-firms-alabama) (135)
- [Professional services firms in Minnesota](https://www.tamtam.ai/l/professional-services-firms-minnesota) (125)
- [Professional services firms in New York](https://www.tamtam.ai/l/professional-services-firms-new-york) (735)
- [Professional services firms in Chicago](https://www.tamtam.ai/l/professional-services-firms-chicago) (196)
- [Professional services firms in Houston](https://www.tamtam.ai/l/professional-services-firms-houston) (156)
- [Professional services firms in Atlanta](https://www.tamtam.ai/l/professional-services-firms-atlanta) (143)
- [Professional services firms in San Francisco](https://www.tamtam.ai/l/professional-services-firms-san-francisco) (130)
- [Professional services firms in Washington](https://www.tamtam.ai/l/professional-services-firms-washington) (109)
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Source: https://www.tamtam.ai/l/professional-services-firms-oklahoma