The judging panel - which also includes Diane Foreman and Dan Radcliffe - said Harris knew his business inside out and was "very modest but with a very good story to tell".
When Harris took the helm at CBL Corporation, the business had two workers and one office.
Over 17 years, managing director Harris has grown the company to become an international specialist insurer and reinsurer with almost 550 employees across 25 countries.
Harris began as an accountant for the Fletcher Group and moved into insurance in 1989 as an executive director of Boston Marks Group.
CBL has achieved an annual growth rate of 37 per cent and more than 98 per cent of revenue is derived from overseas markets.
Harris will represent New Zealand at EY's World Entrepreneur Of The Year event in Monaco next June, competing for the title with winners from more than 50 countries.
Other category winners vying for the top title tonight were:
• Turbo staff's Ihaka Rongonui
• Dairyworks' Peter Cross
• RedShield Security's Andy Prow
• Onguard Group's Will Lomax
Two other awards presented at tonight's event were the Family Business Award for Excellence, which went to the chocolate-making Whittaker family, and the Exceptional Services to Entrepreneurship Award, given to publisher Dame Wendy Pye.