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26,462 companies in Ontario, California.
Find 26,462 companies in Ontario, California. From manufacturers to industrial suppliers, each listing carries the firm's address, website, size, and NAICS/SIC codes. You can also browse nearby cities such as Los Angeles, San Francisco, San Diego.
Ontario, California companies by size and revenue
| Employees | Companies | Share |
|---|---|---|
| 1-50 | 25,439 | 97.0% |
| 51-200 | 608 | 2.3% |
| 201-1000 | 157 | 0.6% |
| 1001-5000 | 22 | 0.1% |
| 5001+ | 5 | 0.0% |
| Revenue | Companies | Share |
|---|---|---|
| Under $10M | 24,782 | 97.0% |
| $10M-$50M | 639 | 2.5% |
| $50M-$250M | 105 | 0.4% |
| $250M-$1B | 21 | 0.1% |
| $1B+ | 5 | 0.0% |
Share is of companies with a known value — 26,231 with headcount and 25,552 with revenue on file, as of Jul 17, 2026.
Frequently asked questions
How many companies are in Ontario, California?
26,462 companies in the directory are located in Ontario, California.
How many large companies are in Ontario, California?
61 of the 26,462 companies in Ontario, California employ more than 500 people, and 5 report over $1 billion in annual revenue. See the size and revenue breakdown above for the full distribution.
What size are most Ontario, California companies?
Most are small and mid-sized businesses: the size and revenue tables above show the full spread, from under $10M up to $1B+, across the 25,552 companies with revenue on file.
What information is included for each company?
Every listing includes the company name, location, website, employee size, revenue range where available, and NAICS/SIC classification, with a link to the full profile.
Where does this directory come from?
Listings are compiled and maintained by Factur, a sales and marketing firm for B2B manufacturers. Any company can request an update or removal from its profile page.