Still, Ms. Park will have to contend with the fallout from that success, and her father’s role in it. One of the abiding themes of the campaign was the clamor for more economic equality and a reining in of the chaebol, or family-controlled conglomerates like Samsung, that Mr. Park helped build with government largess. Those companies power the economy, but their unruly expansion in recent years is blamed for aggravating the gap between rich and poor.

In the end, South Koreans appeared to prefer Ms. Park’s calls to overhaul the chaebol over time to the more aggressive approach suggested by her rival, Mr. Moon. Indeed, what appeared to separate the two candidates throughout the election was how far they would go in implementing change.

Mr. Moon campaigned on a return to the Sunshine Policy, a combination of investments and aid to the North. Although Ms. Park criticized the “inflexible” hard-line policy of the incumbent, President Lee Myung-bak, for failing to tame North Korea, she prefers a cautious rapprochement. She said she would decouple humanitarian aid from politics and try to meet the new North Korean leader, Kim Jong-un. But she insisted, like Mr. Lee, that any large-scale investments be conditional on progress in ending North Korea’s nuclear weapons program.

While Ms. Park’s stance may pose something of a challenge to the Obama administration’s policy on North Korea — which had been in lock step with Mr. Lee’s — analysts say it will be much easier for the United States to work with her on the issue than with Mr. Moon.

On Wednesday, President Obama congratulated Ms. Park in a statement, while noting “admiration for all President Lee has done to strengthen relations” between the United States and South Korea. Mr. Lee could not run again for president because of term limits.

Ms. Park’s political career was born in family tragedy. Her mother was killed by a Communist agent in 1974 when Ms. Park was 22 and a student in Paris; she abandoned her studies to return to Seoul and serve as acting first lady. Five years later, her father was assassinated by his disgruntled spy chief.