The Tunisian state news agency reported his death. He had been treated for prostate cancer and was hospitalized last week.

His death came four days after Tunisians voted in their second free presidential elections since his ouster, further solidifying their nation’s status as the purest direct democracy in the Arab world.

Mr. Ben Ali was the first of the autocrats to be ousted in the uprisings that roiled the Middle East nearly nine years ago. He fled Tunisia with his family in January 2011 for Saudi Arabia, where the ruling monarchy allowed him to live quietly, rejecting Tunisian requests for his extradition to stand trial at home.

Six months after he fled, a Tunisian court sentenced him and his wife, Leila Trabelsi, to 35 years in prison and a $66 million fine after a trial in absentia for embezzlement and corruption.

He was also accused of possessing illicit drugs, guns and purloined archaeological treasures in his palaces, as well as ordering the killings of those who opposed his 23-year grip on power.

His disregard for the plight of fellow citizens was embedded in history when a fruit seller named Mohamed Bouazizi immolated himself after a confrontation with the police, setting off the protests that toppled Mr. Ben Ali.

While few Tunisians miss his rule, many acknowledge that life has gotten more difficult since the revolution, with high unemployment and inflation hurting Tunisian families and jihadist attacks damaging the country’s vital tourist sector.

Mr. Ben Ali held a number of top security positions during the 1970s and ′80s before being named the Tunisian ambassador to Poland. In 1984, he was summoned home to quash a series of bread riots.

That led to his appointment as interior minister and then prime minister in 1987. Less than three weeks later, he brought in a team of doctors to declare Mr. Bourguiba senile and unfit to rule. Mr. Bourguiba’s removal made Mr. Ben Ali president.

He consolidated power in Tunisia as Algeria, his small North African nation’s neighbor to the west, descended into civil war and as Libya, neighboring on the east, was dominated by the strongman Muammar el-Qaddafi.

Mr. Ben Ali, by contrast, appeared at the time to be a reformer, speaking of opening up the economy and making progress toward democracy. He abolished the title of “President for Life,” which his predecessor had used, and limited presidential terms to three. He also launched initiatives to expand the social security net and promote education and women’s rights.

“I needed to re-establish the rule of law,” Mr. Ben Ali said in an interview with a French television station after taking power. “The president was ill, and his inner circle was harmful.”

But once in office he built a police state that crushed all forms of dissent and nurtured a cult of personality. Photos of Mr. Ben Ali — his hair jet black, his face unlined, his body cloaked in dark suits — were ubiquitous, on billboards and in classrooms and government offices throughout the country.

In his first 10 years in power, Tunisia experienced economic growth as a result of widespread economic restructuring supported by international institutions.

But the expansion paved the way for corruption, in which Mr. Ben Ali’s relatives were seen to be the most prominent beneficiaries.

His wife, Ms. Trabelsi, had been working as a hairdresser when he met her, and she gave birth to their first daughter while he was still married to someone else. He married Ms. Trabelsi after coming to power, and she became the focus of great hatred by many Tunisians for her extravagant lifestyle and promotion of her relatives.

In private, Tunisians complained that their country had become a mafia state run by “the Family.” It was understood which family that was.

“Even the police report to the Family!” one Tunisian complained to an American diplomat in 2008 in a cable later released by WikiLeaks.

“With those at the top believed to be the worst offenders, and likely to remain in power, there are no checks in the system,” the diplomat wrote.

Mr. Ben Ali’s promised democratic reforms never happened. He organized Tunisia’s first multicandidate presidential election in 1999 — and he handily won, with more than 99 percent of the vote.

Three years later, he held a referendum that allowed him to serve a fourth term; he ultimately did away with term limits altogether.

His rule faced an unexpected threat in 2010, when Mr. Bouazizi, an unknown fruit seller in a poor Tunisian town, set himself on fire after a confrontation with the police. The funeral of the fruit seller grew into a series of antigovernment protests that chased Mr. Ben Ali into exile in January 2011.

His ouster inspired young people across the Arab world, and similar protests soon erupted in Egypt, Libya, Bahrain and Yemen. In the succeeding years, three other longtime Arab strongmen were pushed from power, while Syria, Yemen and Libya collapsed into war.

Saudi Arabia’s ruling monarchy protected Mr. Ben Ali from extradition while he was prosecuted in absentia in Tunisia’s judicial system. In 2012, he was sentenced to life in prison for his role in the killings during the uprising.

He all but disappeared from public view in his later years, with the exception of a few social media posts by one of his sons. One showed him sitting on a couch in a white shirt and glasses. Another showed him in striped pajamas sitting behind a model skeleton.

His family’s lawyer, Mounir Ben Salha, said Mr. Ben Ali would be buried in Saudi Arabia.