Sam Panopoulos displays his 1962 invention, the Hawaiian pizza, in 2010. Panopolous died June 8, 2017, in a London, Ontario hospital. He was 83. (Derek Ruttan/Postmedia Network File Photo)

When the American inventor Samuel Morse visited 19th-century Naples, the birthplace of the modern pizza, he described that city’s preferred street food as “a piece of bread that had been taken reeking out of the sewer.”

A century later, a 20-year-old Greek named Sam Panopoulos found himself similarly disappointed. Stopping in Naples during a 1954 voyage to Canada, he found his first taste of “pizza” — a bun topped with sauce and spaghetti — uninspiring.

Yet Mr. Panopoulos, who opened a restaurant in Chatham, Ontario, called Satellite, eventually warmed to the yeasted flatbread that Neapolitan bakers had popularized in the 1700s and that Greek chefs had whipped up for sailors more than a thousand years before.

Searching for new pizza flavors one day in 1962, he reached for a can of fruit and launched a culinary revolution, topping his restaurant’s standard cheese pizza with bits of ham and pineapple. The result was sweet, sour and savory — a flavor combination hailed ever since as both revelatory and repugnant, a Canadian treasure and a “Polynesian perversion.”

For pizza partisans around the world, especially those who saw it as an oven-baked abomination, it prompted the same question that Morse posed in his first long-distance telegraph message: “What hath God wrought?”

Mr. Panopoulos, who is widely credited with having created and named the Hawaiian pizza, died June 8 at 83, four months after his fruit-laden, at times politically polarizing creation triggered a spat between the leaders of Iceland and Canada.

His pizza was part of a long tradition of experimentation, said Carol Helstosky, a culinary scholar at the University of Denver who has written about the history of pizza. “In Naples, it was a cuisine of scarcity: Whatever you had, you tossed it on — garlic, anchovies, other little fish bits.”

By the 1950s, she said, pizza was acquiring widespread popularity in the United States, and newspapers ran recipes that featured toppings such as liverwurst and onions. Pepperoni didn’t become a common topping until the early ’70s.

“The pizza in those days was primitive, you know?” Mr. Panopoulos told the website Atlas Obscura in 2015. The dish wasn’t available in Chatham, so Mr. Panopoulos and his two brothers drove to restaurants in Detroit, 50 miles west. There, topping ­choices were limited to mushrooms, bacon and pepperoni.

Satellite, the restaurant he started with his siblings, sold standard diner fare and Chinese food — “a pile of Chinese food,” Mr. Panopoulos said, at the suggestion of a Chinese resident who noted that no other restaurants in the area offered the cuisine — before expanding to pizzas. Pineapple was soon added as a topping, and the pizza was named Hawaiian because of the brand of canned fruit Mr. Panopoulos used.

The pies turned out to be a hit, he said, in part because most other restaurant food was bland or boring. “People didn’t go for a lot of different tastes and foods,” he told the BBC in February. “The only thing you could find then sweet-and-sour was Chinese, nothing else. Everything else was plain.”

Pizza boxes, like the food itself, were improvised, made using cardboard from a nearby furniture store.

Mr. Panopoulos in 1975 sold Satellite, where the Hawaiian pizza is still on the menu ($21 Canadian for a large), and moved to London, Ontario, to operate a restaurant called the Family Circle. In an obituary, his family announced his death at a London hospital but did not disclose the cause. He was 83.

Mr. Panopoulos appeared perplexed at times that his pizza was hated by so many, sometimes including heads of state.

The president of Iceland, Gudni Thorlacius Johannesson, told a group of high-schoolers in February that he was “firmly opposed” to pineapples on pizza and would like to ban the topping. In Canada, where the Hawaiian pizza ranks alongside maple syrup and poutine as a national culinary treasure, Prime Minister Justin Trudeau responded by tweeting the hashtag “#TeamPineapple” in support of “this delicious Southwestern Ontario creation.”

Johannesson soon issued a statement on Facebook, writing: “I like pineapples, just not on pizza. I do not have the power to make laws which forbid people to put pineapples on their pizza. I am glad that I do not hold such power.”

“For pizzas,” he added, “I recommend seafood.”

Sotirios Panopoulos was born in Vourvoura, Greece, in 1934. Survivors include his wife of 50 years, Christina Panopoulos; two children, Margie and Bill; a sister; and four grandchildren.

Mr. Panopoulos said he wished he had filed for a trademark or patent on his pizza, but at the time believed “it was just another piece of bread cooking in the oven.”

He remained fiercely protective of his creation through the years, insisting that he was the first to use pineapple and meat together on a pizza. When it was suggested that others might have done it first, but that surely there was a chance that Mr. Panopoulos might have created it after all, he seemed almost to have been insulted.

“What do you mean I ‘might have?’ ” he told the London Free Press in 2010. “I did.”