He died at his winter home in Vero Beach, Fla., on Dec. 19, according to a death notice. He was 85.
"'This Hour Has Seven Days' inspired us, a whole generation of us. It certainly redefined the documentary in Canada," said Mark Starowicz, executive director of documentary programming at CBC-TV.
"With no exaggeration, to this day we use approaches and techniques that were incubated under Douglas Leiterman."
The native of South Porcupine, Ont., got his start in journalism in British Columbia before going on to become a Parliament correspondent for the Southam News Service in Ottawa. He then joined the CBC and worked on a number of documentary series, including "Document," which he executive produced with Patrick Watson.
He and Watson would go on to launch "This Hour Has Seven Days" in 1964, a genre-bending mix of hard-hitting news and interviews alongside edgy comedy and satire.
During celebrations of its 75th anniversary, the CBC called it "the most defiant and controversial program in Canadian broadcasting history."
"It was a show that courted controversy both in the news and internally at CBC. The producers were really quite aggressively anti-authority with the CBC and they didn't back down from challenges," said Blaine Allen, an associate professor at Queen's University's department of film and media.
"They showed Canada to itself quite vividly. They also showed elements of the world to Canadian audiences in ways that I think Canadian news hadn't really done before."
Despite drawing millions of viewers, CBC brass yanked the unpredictable show off the air after just two seasons, sparking a public uproar that reverberated all the way up to the office of then-prime minister Lester B. Pearson.
"It was just breathtakingly bold, outrageous — in the best sense of the word — pugnacious; we'd never seen journalism like that," said Starowicz.
"It just rocked the country, it was just unbelievable. No one had seen anything like it."
Leiterman would leave the CBC after the show's cancellation and continued to work on documentaries through his company Hobel-Leiterman Productions.
He is survived by his wife of 50 years, Beryl Fox, his daughters Lachlan, Catherine, Julia and Barbara, and sister Phyllis King.
No funeral is planned, but a celebration of his life is to be held in May.
Leiterman's death came within days of colleague Laurier LaPierre's passing. The co-host of "This Hour Has Seven Days" died at age 83 on Dec. 16.
"It makes you conscious of how that generation is passing," said Allen.