The May 9 vote takes place under the shadow of North Korea’s growing nuclear threat, but voter sentiment is squarely focused on inequality and unemployment -- echoing the forces that have seen political norms upended in Britain and the US.
Park’s dismissal by the country’s top court came after months of political turmoil in Asia's fourth-largest economy, which saw millions take to the streets to call for her ouster over a wide-ranging scandal.
At one level, the demand for change will be fulfilled on Tuesday. The South has been ruled by conservatives, including both Park and her father, for all but little more than a decade of its existence.
But left-leaning former human rights lawyer Moon Jae-In is set for a crushing victory at the ballot box according to the final opinion polls released Thursday -- South Korean law bans surveys carried out in the last week of the campaign being published before the vote.
In a field of 15 candidates, a Realmeter poll put Moon on 42.4 percent, with centrist Ahn Cheol-Soo and conservative Hong Joon-Pyo, of Park's Liberty Korea party, tied on 18.6 percent.
Gallup Korea gave Moon 38 percent, with Ahn second on 20 percent, followed by Hong with 16 percent.
"This will be a wipeout of the South Korean right akin to what happened to the Republican Party in the United States after Watergate," said Robert Kelly of Pusan National University.
A high turnout is expected -- even more than the last vote's 75.8 percent -- with one National Election Committee official describing public attention as "more intense than we ever expected".
Broken promises
But the winner will still have to deal with the slowing growth, mounting inequality and unemployment -- especially among young people -- that fuelled anger at Park's conservative government.
The South's decades-long "Miracle on the Han" saw it rise from war-ravaged ruin to the ranks of the OECD, but joblessness among under-30s hit a record 10 percent last year and is expected to rise further this year, while wages are stagnant.
At the other end of the social scale, the top 10 percent of South Korean earners account for nearly half of overall income, according to a study by the International Monetary Fund published last year -- the highest ratio in Asia.
Park is awaiting trial on charges including abuse of power and corruption for offering policy favours to top businessmen who bribed her secret confidante, Choi Soon-Sil, including Samsung heir Lee Jae-Yong.
The scandal exposed the cosy and corrupt ties between politicians and the country's powerful family-run conglomerates, known as chaebols.
It has heightened calls for reform of the firms, and all the candidates vow to do so.
But the firms are a hugely significant part of the economy and retain much support for their role in the country's growth, so that similar campaign promises by many former South Korean leaders have gone unfulfilled.
"Whoever becomes the next president, he will have his job cut out for him given the daunting tasks that await him," said former prime minister Kim Hwang-Shik.
"The host of problems entangled with each other will take a long time for the next leader to solve -- if they can be solved at all," he wrote in an essay published by Maeil business daily.
'Back on its feet'
The Blue House's next occupant will also find themselves plunged into high tensions with North Korea and uncertainty over the relationship with key ally and protector the United States.
Fears have mounted as the nuclear-armed North staged a series of missile launches and speculation swirled that it could conduct a sixth atomic test.
Washington has made threatening noises about potential military options -- although in the event of retaliation, that could rapidly spiral into devastation for Seoul, which lies within range of Pyongyang's artillery.
The deployment of the Terminal High Altitude Area Defense (THAAD) battery also marred ties with China -- the South's largest trading partner -- while US President Donald Trump said Seoul should pay for the system and urged renegotiation of a bilateral free trade pact between the allies.
But South Koreans are used to living with the threat from the North, and the downfall of Park -- a conservative icon -- has limited the issue's prominence in the campaign.
"More and more people, especially young or swing voters, feel fed up with the same old talk of 'North Korean sympathisers' that come out in every single election campaign," said Kang Cheol-Koo, analyst at Korea Society Opinion Institute.
Park's impeachment and Tuesday's vote were "unique, but it isn't a crisis", Kelly told AFP.
"Scandals happen in democracies, the real question is how do they deal with them," he said.
After the vote, he added, the country "will be back on its feet, it will have a normally elected president, things should move on".
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