David Johnston said he is proud to have the opportunity to serve as Canada's next governor general, a position he will begin serving in this fall.

Speaking to reporters in Ottawa, the smiling governor general-to-be spoke about his prior career in academia, which gave him "the good fortune to witness Canadians' creativity and ingenuity, our strong ties to our communities…as well as our diversity and our vitality," Johnston said Thursday morning. "The opportunity to see these values at work across the country means a great deal to me."

Vowing to "be a stalwart defender of our Canadian heritage, of Canadian institutions and of the Canadian people," Johnston gave a glimpse of the approach he will bring to Rideau Hall.

He also said he looks forward "to meeting with the brave men and women of the Canadian Forces." When he becomes governor general, Johnston will also be the commander-in-chief of Canada's military.

Currently the president of the University of Waterloo, Johnston is a career academic and respected lawyer who previously served as the principal and vice-chancellor of McGill University in Montreal. He has also held teaching positions at several Canadian universities.

Earlier Thursday, Prime Minister Stephen Harper formally announced that Johnston would be the next governor general and will assume his new duties on Oct. 1, replacing the outgoing Gov. Gen. Michaelle Jean.

Pointing to Johnston's record of public service and experience in law, Harper said the incoming governor general has "a comprehensive understanding of government and a deep appreciation of the duties and tasks now before him."

"David Johnston represents the best of Canada," Harper said in a statement.

"He represents hard work, dedication, public service and humility. I am confident he will continue to embody these traits in his new role as the Crown's representative in Canada."

Officials say Johnston met Queen Elizabeth when she was in Toronto earlier this week.

CTV's Ottawa Bureau Chief Robert Fife said Johnston met the Queen at a state dinner held at the Royal York hotel.

It is expected that he will travel to Buckingham Palace later this summer for discussions with the Queen.

The selection of Johnston as the next governor general reverses a recent trend that saw journalists appointed to the job.

The most recent three governors general -- Michaelle Jean, Adrienne Clarkson and Romeo LeBlanc -- all worked in journalism during their careers.

Johnston, however, is well familiar with the political scene in Ottawa.

Fife said Johnston is respected as a non-partisan academic who has worked with both the Liberals and Conservatives in the past, a reputation the Prime Minister's Office alluded to when announcing his appointment.

"His exemplary record of public service has earned him the respect, support and admiration of many prominent Canadians in politics, government, academia, parties of all stripes, and in every region of the country," said a news release posted to the Prime Minister's website.

Johnston was selected to write the terms of the Oliphant inquiry that examined the business dealings former prime minister Brian Mulroney had with German-Canadian businessman Karlheinz Schreiber.

Johnston has also hosted major Canadian leadership debates, including one between Mulroney and then-prime minister John Turner in 1984.

He has studied at Harvard, Cambridge and Queen's University in Ontario.

Johnston became a Companion of the Order of Canada in 1997. He first became an Officer of the Order of Canada in 1988.

With files from The Canadian Press