He received the honour at a gala ceremony held at the London Sky Bar on Thursday 26 June.
The judging panel consisted of eight inspirational people led by chairman of justgiving.com Jonathan McKay.
Grenville Turner, chief executive of Countrywide, said: “I am very proud to win this award and would like to thank the judges and everyone at Countrywide for all their hard work and support.
“I firmly believe these awards are a team effort and recognition for every valuable member of the Countrywide team and its many supporters including clients and investors of the remarkable journey that the group has been on since 2007.”
Turner steered the property services group through a tough period since joining in 2007, immediately leading them through a management buyout.
Since then he has helped Countrywide grow organically and through acquisition, returning the company to the public markets in 2013.
The EY Entrepreneur of the Year programme celebrates business leaders in more than 145 cities and 60 countries worldwide.