MANILA — Former Philippine president Benigno Aquino III, a scion of pro-democracy leaders who helped topple dictator Ferdinand Marcos in the 1980s, and a staunch campaigner in his own right against domestic corruption and China's expansive territorial claims, died June 24 in a Manila hospital. He was 61.

The cause was renal failure as a result of diabetes, his family said in a statement.

Mr. Aquino, who was elected as the Southeast Asian country’s 15th president in 2010, largely stayed out of the public eye after leaving office in 2016. (Philippine presidents are limited to a single six-year term.) He had spent the last years of his life in poor health, his family said.

Widely known by his nickname “Noynoy,” he was the son of two icons of Philippine democracy: Benigno Aquino Jr., a former senator who was assassinated upon his return from exile in 1983, and Corazon Aquino, a homemaker who rose to lead the opposition to the Marcos’s autocratic rule after her husband’s death.

Corazon Aquino became president after Marcos was ousted in the Philippines’ 1986 “people power” revolt, which followed a snap election in which Marcos had claimed victory thanks to widespread fraud. The turbulent years of her presidency from 1986 to 1992 were marked by repeated military coup attempts. During one of them, in 1987, Mr. Aquino was shot five times by rebel soldiers while returning to the presidential palace in a car, and three of his bodyguards were killed. One bullet remained lodged in his neck for the rest of his life.

After his mother died of cancer in 2009, Mr. Aquino, who by then had served several terms in the Philippine Congress, parlayed his name recognition and a wave of pro-democracy, anti-corruption sentiment into election as president. He ran on the slogan, “No corruption, no poverty.” Although he had neither the charisma of his father nor the broad, almost saintly appeal of his mother, he won in a landslide, easily beating a predecessor, discredited former president Joseph Estrada, whose term had been cut short by impeachment on graft charges.

A chain smoker who spent much of his free time playing video games and was known for a low-key personality and short attention span, Mr. Aquino told The Washington Post in 2010 that he “wasn’t thinking of running” after his mother’s death.

“I wasn’t clamoring to be the person responsible for solving all the problems,” he said.

But an outpouring of grief for his mother contributed to a wave of support for his candidacy, and he entered the race after a period of contemplation at a convent.

“I accept the challenge to lead this nation,” he said, according to the New York Times. “I want to make democracy work, not just for the rich and well connected, but for everybody.”

A member of one of the country’s most prominent landowning families, Mr. Aquino promised economic reforms, a crackdown on tax evasion and punishment of corrupt officials. His administration was credited, particularly in the early years of its term, with stabilizing the economy. Gross domestic product grew by more than 6 percent annually between 2012 and 2015.

Mr. Aquino also succeeded in getting the Moro Islamic Liberation Front, a large insurgent group, to renounce violence after decades of armed conflict. Negotiations paved the way for an autonomous region in the Catholic-majority country’s south, where most of the Philippines’ Muslims live.

In international affairs, his presidency is perhaps best remembered for his firm stance on Philippine territorial rights in the South China Sea. The Aquino administration led a case before the Permanent Court of Arbitration, based in The Hague, against China’s claim to virtually the entire South China Sea, including islands close to the Philippines. The court ruled in favor of the Philippines in July 2016, after Mr. Aquino had left office. But China rejected the tribunal’s ruling, and President Rodrigo Duterte, who succeeded Mr. Aquino, has largely avoided confronting Beijing.

Mr. Aquino’s government, however, was heavily criticized for its handling of Typhoon Haiyan, which killed thousands of Filipinos in 2013. His popularity also took a hit from a botched police operation to capture Muslim rebels in 2015 that left 44 officers dead. Analysts said dissatisfaction with his government eventually led to the rise of the populist Duterte, a political opponent of Mr. Aquino.

Benigno Simeon Cojuangco Aquino III was born Feb. 8, 1960, in Manila. His father was imprisoned after Marcos declared martial law in 1972 to remain in power. The elder Aquino was allowed to seek treatment in the United States after he suffered a heart attack in prison in 1980.

After finishing a degree in economics at Ateneo de Manila University in 1981, the younger Aquino joined his family in exile in the Boston area. There, he helped his parents as a “jack of all trades,” he later told a Philippine television channel. “I was the assistant driver, handyman, gardener, electrician, plumber [and] dog handler.”

Upon returning to the Philippines with his family after his father was assassinated, Mr. Aquino worked in business, notably as a promotions manager for Nike and later as a vice president of an uncle’s insurance company, and he helped run his family’s 11,000-acre estate in their native Tarlac province.

In late August 1987, a car carrying Mr. Aquino came under fire from rebel soldiers as he was attempting to return to the Malacañang Presidential Palace during a coup attempt against his mother. He was wounded, and three of his four bodyguards were killed. The attackers fled, and the rebels largely escaped punishment. Col. Gregorio Honasan, the coup leader, was held for several months, but he later was granted amnesty and became a senator.

As president, Mr. Aquino was known for his honesty and his anti-corruption efforts, a welcome change from the previous two administrations. But his stoical, matter-of-fact demeanor often came across as a lack of empathy, and entrenched interests limited his ability to achieve his goals.

“He reformed the country, but not radically,” said political analyst Antonio La Viña. “He was a modern president, but not modern enough to fix the political system.” And despite the Philippines’ growth rates, his economic stewardship “wasn’t successful in terms of equality,” La Viña said.

Vice President Leni Robredo, a member of Mr. Aquino’s Liberal Party, wrote on Twitter: “He tried to do what was right, even when it was not popular.”

A lifelong bachelor, Mr. Aquino had relationships with several women before and during his term in office, including South Korean television host Grace Lee. He had no children. Survivors include four sisters.

Mr. Aquino credited his parents with imbuing in him the desire to “take up the cudgels for those who have less in life, for the powerless,” he told Time magazine in 2010 while running for president.

In his inaugural address months later, he told a large crowd in Manila’s Rizal Park: “My parents sought nothing less, died for nothing less, than democracy and peace. I am blessed by this legacy. I shall carry the torch forward.”

Branigin reported from Washington.