Lee Kun-hee, pictured in 2010, transformed Samsung Electronics in his three decades of leadership. (Lee Jae Won/Reuters)

Lee Kun-hee, who built Samsung Electronics into a global tech giant but whose tenure was marred by a pair of white-collar crime convictions that were wiped away by presidential pardons, died Oct. 25. He was 78.

His death was announced by Samsung, which did not specify the cause. Mr. Lee had been treated for lung cancer in the late 1990s and was incapacitated for years after a 2014 heart attack that led his son, Jae-yong, to take over running the company.

“Chairman Lee was a true visionary who transformed Samsung into the world-leading innovator and industrial powerhouse from a local business,” the company said in a statement.

Under Mr. Lee’s three decades of leadership, Samsung Electronics grew from a small television maker into the world’s biggest producer of smartphones, electronic displays and memory chips. He was convicted of bribery and then tax evasion but pardoned in both cases.

Mr. Lee was born in Daegu, in Japanese-occupied Korea, on Jan. 9, 1942. His father, Lee Byung-chul, founded Samsung as a small trading company in the southeastern city. Mr. Lee inherited the company in 1987 and embarked on a quality-improvement drive to rid it of a reputation for producing cheap copycat appliances.

Mr. Lee called it a “life-or-death situation” and advised executives: “Change everything except for your wife and children.” In its statement Sunday, the company remembered the moment: “His 1993 declaration of ‘New Management’ was the motivating driver of the company’s vision to deliver the best technology to help advance global society.”

Samsung and South Korean flags fly outside a company building in Seoul on Sunday. (Jung Yeon-Je/AFP/Getty Images)

In 1995, he famously ordered nearly $50 million worth of cellphones and fax machines set on fire, citing low quality. The bonfire was watched by 2,000 Samsung employees who wore headbands reading “Quality first,” according to news media reports at the time.

Samsung Electronics is the flagship of Samsung Group, a sprawling powerhouse with dozens of affiliates that stretch into shipbuilding and life insurance. The group is the largest and most powerful of South Korea’s chaebol, family-controlled conglomerates that dominate the economy.

Many chaebol tycoons, including Mr. Lee, were convicted of white-collar crimes but then granted pardons as the Korean government and the public sought to prevent any economic fallout from their absence.

Mr. Lee was convicted twice, but his jail sentences were suspended by the courts both times, a common practice that helped executives return to work.

In 2008, he stepped down from the leadership after he was convicted of managing slush funds and evading taxes to pass company shares to his children. He retook the helm two years later after a presidential pardon, given so that he could resume his work on a lobbying campaign that brought the 2018 Winter Olympics to -PyeongChang. His other pardon was in 1997, after he was convicted of bribing a former president.

Mr. Lee’s business empire was involved in a corruption scandal that led to the impeachment of President Park Geun-hye, who was replaced by President Moon Jae-in in 2017. Moon has promised to end the practice of pardoning convicted corporate leaders.

Mr. Lee’s son, Lee Jae-yong, Samsung’s de facto head, was sentenced to five years in prison for bribing Park and her confidant to help secure his control over Samsung. He spent a year behind bars before an appeals court reduced his sentence and released him.

Mr. Lee was considered the richest person in South Korea, with a net worth that Forbes estimated at more than $17 billion.

In addition to his son, survivors include his wife, Hong Ra-hee; and two daughters, Boo-jin and Seo-hyun. Another daughter, Yoon-hyung, died by suicide in 2005.

Moon will send condolence flowers to the funeral, spokesman Kang Min-seok said Sunday. Samsung has yet to announce succession plans for the opaque three-generation dynasty under which it has operated.