SECWYN

Professional Services Companies in California: 215 Verified Firms

Secwyn has verified 215 professional services companies based in California. The largest groups are Temporary Help Services (64); Employment Placement Agencies (44); and Engineering Services (44). By headcount, 73% have 51–200 employees, 20% have 201–500 employees, and 8% fall in other size bands. Size is not yet confirmed for 2. San Francisco has the most (22), followed by San Diego (19) and Los Angeles (15).

Company size

  • 11–50 employees9 · 4%
  • 51–200 employees155 · 72%
  • 201–500 employees42 · 20%
  • 501–1,000 employees7 · 3%
  • Size not confirmed2 · 1%

Top cities

  • San Francisco22 · 10%
  • San Diego19 · 9%
  • Los Angeles15 · 7%
  • Irvine12 · 6%
  • San Jose7 · 3%
  • El Segundo5 · 2%
  • Orange5 · 2%
  • Santa Clara5 · 2%
  • Anaheim4 · 2%
  • Fresno4 · 2%

Cities with fewer than 3 companies are not listed.

Largest sub-industries

Sub-industryCompanies
Temporary Help Services64
Employment Placement Agencies44
Engineering Services44
Architectural Services27
Landscaping Services12
Executive Search Services6
Janitorial Services3
Landscape Architectural Services3

A sample of these companies

A few of the 215 professional services companies in California. Names, websites and contacts are shown after you sign up.

  1. Company #1 · name shown after sign-up

    Landscaping Services · 51–200 employees

  2. Company #2 · name shown after sign-up

    Employment Placement Agencies · 51–200 employees · Irvine

  3. Company #3 · name shown after sign-up

    Engineering Services · 51–200 employees · San Diego

  4. Company #4 · name shown after sign-up

    All Other Business Support Services · 201–500 employees · Santa Clara

  5. Company #5 · name shown after sign-up

    Temporary Help Services · 51–200 employees

  6. Company #6 · name shown after sign-up

    Architectural Services · 201–500 employees · Orange

Find the California professional services companies that fit what you sell

Describe what you sell and Secwyn shows the companies most likely to buy it, with the reasons for each match. Sign up free and your first 3 company reveals are on us: name, website, description with its source, contact channels and the roles to contact.

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How Secwyn verifies these companies

  • Every company description is a sentence visible on the company's own website. Inside the product, each one links to its source page.
  • Each company has a NAICS industry code, the US government standard for classifying businesses.
  • All companies are based in the United States. Location and size come from public sources, including company filings and People Data Labs.

Data updated October 6, 2026.