The daily newspaper said Dennis died Thursday at his home in Halifax after a brief illness. He was 84.
Dexter said in a release that Dennis, who was publisher of the Chronicle Herald for 57 years, leaves behind an important legacy.
The release from the premier's office said Dennis, who oversaw one of the few remaining independent newspapers in the country, held the longest record of service of any Canadian newspaper publisher.
Arthur Irving, chairman of Irving Oil Co., said he was saddened by the passing of a "good guy" who was "always a pleasure to be with."
He recalled Dennis as a man of conviction who knew what he wanted to do and went out and did it.
"He ran a good newspaper and that was absolutely his life, to run a good newspaper," said Irving, who first met Dennis when he came to visit his father, K.C. Irving.
Former prime minister Paul Martin said he met Dennis as a young MP and would visit him almost every time he came to Halifax.
"We would sit down and discuss politics quite philosophically, if I recall," said Martin. "He was a man of very strong and also very deep opinions, and somebody that I admired enormously."
Ian Thompson, associate publisher of the Chronicle Herald, issued a statement on Thursday night on behalf of the family.
He described Dennis as a great Nova Scotian who was loyal to his province, newspaper and his employees.
“Notably, he died on Dec. 1, the anniversary of what he often said was his proudest moment: the 1950 start of the pension plan for Herald employees,” Thompson said.
Allan Shaw, non-executive chairman of the Shaw Group, remembered Dennis for his old-fashioned elegance and the way he walked to work "always in a suit; often three-piece," and the courteous way he would greet people: "How are you today, sir?"
Born in Halifax, Dennis became publisher in the days of typewriters and telegraphs and presided over operations well past his 80th birthday.
Despite a diminishing role in recent years, he regularly came into his office very late into his life. He had been in failing health for some time and had recently taken a turn for the worse.
He was the third generation Dennis to run the newspaper. His father, Sen. William Henry Dennis, and his great-uncle, Sen. William Dennis, preceded him.
The role of chief executive officer for the newspaper is now held by his daughter, Sarah Dennis, who along with her sister, Heather, and Dennis's wife, Gay, were with him in his final hours.
His son, William, died in 2002 at age 30.
Dennis was fiercely proud of the Herald's independence, telling visitors to his office about the many offers that had been made to buy it over the years. All were rebuffed politely, but firmly.
“He loved his newspaper and he loved Nova Scotia,” said Dexter. “He will be remembered as a fine businessman, and a great Canadian.”
(Halifax Chronicle Herald)