Miami didn't even make NerdWallet's top 10 in 2012, but the city's rapid population growth is helping drive small business activity.
"Miami's biggest advantage is its very diverse population," said Tony Argiz, chairman of the Greater Miami Chamber of Commerce.
These new transplants, who hail from Cuba, Colombia, Argentina -- and more recently Mexico and Venezuela -- "are very entrepreneurial by nature," Argiz said.
Budding business owners have access to several incubators, including the nonprofit Miami Entrepreneurship Center, which offers free co-working space downtown.
Miami Dade College's Minority & Small Business Enterprise Office focuses on helping develop minority and women-owned small businesses.
"What we don't have here, other than the cruise companies, are big business employers," said Argiz. "So people naturally gravitate toward starting a business."