The black-and-white photograph, taken at Buckingham Palace in March, shows the Queen smiling broadly. Bailey described his subject as a "very strong woman" with "very kind eyes with a mischievous glint."
The portrait, unveiled Sunday for the Queen's birthday on Monday, was commissioned for a government campaign to promote Britain's heritage and tourism to potential visitors abroad.
Britain's monarchy and royal history is one of the biggest drivers of its strong tourism industry.
The Queen celebrates two birthdays each year: Her actual one on Apr. 21 is celebrated privately, while a public ceremony in June marks the occasion with a Trooping the Color parade in London.