According to the Global Unicorn Club by CB Insights, as of January 2019, there were 325 unicorns -- namely startups with a market value of over US$1 billion -- around the world, including 155 in the United States (47 percent of the total).

Of these 155 unicorns, 102 are located in Northern California, including 82 in Silicon Valley (which usually means the nearly 70-kilometer-long stretch from San Jose to San Francisco), and four in the San Francisco Bay Area. Sixteen unicorns are based in Southern California, including 12 in the Greater Los Angeles area, and four in San Diego.

The remaining 53 unicorns are distributed as follows:
New York City:20
Massachusetts:10 (Boston:6)
Illinois:6 (Chicago:5)
Florida:3
Washington State:3 (Seattle:2)
Utah:2
Georgia:2 (Atlanta)
North Carolina:2
Washington D.C.:1
Tennessee:1
Texas:1 (Austin)
Connecticut:1
Ohio:1

The top sectors in terms of number of unicorns are as follows:
Internet software & services:23
Fintech:16
Healthcare:16
E-commerce:10
Cybersecurity:6
Big data:6
On demand:6
Travel tech:5
Auto tech:5

Source: The Global Unicorn Club as of Jan. 2019
https://www.cbinsights.com/research-unicorn-companies