As of October 16, 2026, ListRiver's records show 8,732 active registered businesses in Diamond Bar, California. 47% are Corporations.
How many businesses are registered in Diamond Bar, California?
ListRiver has 8,732 active registered businesses in Diamond Bar, California on record as of October 16, 2026, from official California business registry data. Dissolved and defunct businesses are not counted.
How many new businesses were formed in Diamond Bar, California in September 2026?
0 businesses on record in Diamond Bar, California were formed in September 2026.
How many new businesses opened in Diamond Bar, California in the last 12 months?
836 businesses on record in Diamond Bar, California were formed in the 12 months through September 2026.
What is the most common type of business in Diamond Bar, California?
Corporations are the most common: 4,128 of 8,732 businesses on record (47%), followed by LLCs with 3,309 (38%).
Where does this data come from?
From California's official business registry. ListRiver loads each new state file, standardizes it, removes duplicates and updates its database weekly. Email and industry details are added from SMBCredit.net where available.
How do I get a list of businesses in Diamond Bar, California?
Use ListRiver's list builder to filter Diamond Bar, California businesses by entity type, formation date, industry and contact details, see the exact count and price, and download a CSV. Every list includes monthly refresh files.
Free to use on any site, and it updates itself every month. Copy this code and paste it into your page. Preview the chart.
Counts come from official California business registry records on file with ListRiver, current as of October 16, 2026. They include businesses that are active on the state register; dissolved and defunct entities are excluded. Contact details are added from SMBCredit.net where available. Formation months reflect the registration date the state reports. See the methodology for sources, update schedules and known limits.