While inequality in South Korea is not necessarily worse than many other countries, the concept has exploded onto the political scene in recent years amid runaway home prices and a stagnating economy, undermining support for President Moon Jae-in.
Moon, in his congratulatory message, said "Parasite" had "moved the hearts of people around the world with a most uniquely Korean story".
But the film's message is a sharp critique of South Korea's modern society, and director Bong Joon-ho turned to many familiar scenes around Seoul to highlight the divide between the city's haves and have-nots.
Across South Korea the divide is visible as some of the old neighbourhoods of crumbling brick slums contrast with the gleaming high-life of Seoul's more swanky spots.
The film uses many of those visual cues to illustrate the competition going on in society, and the sometimes "parasitic" relationships between the rich and poor.
"The uncomfortable exchanges in the movie sparked mixed feelings by hitting a sore spot in society and pitting the rich against the poor," said Kim Chang-hwan, a 35-year-old Seoul resident.
South Korea's economic inequality is higher than many members of the Organisation for Economic Cooperation and Development (OECD), on par with Britain and Latvia, and has worsened in recent years.
Still, its Gini coefficient, a commonly used measure of how evenly income is distributed across the population, is better than places such as the United States, according to the OECD.
But after years of economic growth that powered the country's recovery from the 1950-53 Korean War, South Korean's economic future is more uncertain, causing growing concerns for many.
A 2019 survey by the government affiliated Korea Institute for Health and Social Affairs found more than 85% of South Korean respondents felt there were “very big” income gaps in society and people needed to be from a wealthy family in order to be successful.
Young people have become especially pessimistic amid a highly competitive education system and job market.
That has sent support for Moon plummeting to as low as 45% in early February, as his younger supporters express dissatisfaction with their economic prospects. While Moon is constitutionally barred from running again, a key parliamentary election is due to be held in April, posing a test for his ruling party.
In "Parasite", one character fakes a diploma for her brother to get a job as a tutor for a rich family.
The scene reminded some South Koreans of an ongoing scandal that led to the resignation of Justice Minister Cho Kuk.
Cho resigned in December and is being prosecuted for falsifying documents regarding family investments and efforts to gain university admissions for his children. He has denied wrongdoing.
"Parasite's win is a really great thing, but it was bitter to see the father impressed with his children's forgery skills and their plans to get the jobs," one Twitter user wrote, referring to one of the main characters.
The scandal struck a chord in South Korea where young people, who compete furiously through school and university, are increasingly finding themselves scrambling for a dwindling number of positions in a slack job market, in a system they see as plagued by systemic unfairness and biased in favour of the elite.
The issue was a particular disappointment to the young people who supported Moon and his party when he became president on a platform of cleaning out corruption in the government and business.
(Reporting by Hyonhee Shin; Editing by Josh Smith and Alison Williams) ((email@example.com; 822 6936 1474;))