Ki-woo
Ki-woo is the son of the Kim family, a smart and ambitious young man who feels held back by poverty. After getting referred for a tutoring gig, he orchestrates a plan in which his whole family begins working for the same wealthy family. He has good intentions, even if he is dishonest about how he achieves success, and just wants to create a better life for his family.
After the run-in with Moon-gwang and her husband, Ki-woo becomes exceedingly attached to the lucky rock that his friend gave him, and carries it around as a totem. After Geun-sae bludgeons him with it, Ki-woo emerges from a coma all the more motivated to ascend the class ladder, buy the Parks' home, and reunite with his father, who is living in the subterranean bunker.
Ki-jung
Ki-jung is Ki-woo's sister, a smart and tough young woman who does not suffer fools. She gains the upper hand with Mrs. Park by feigning extreme expertise and confidence, and insisting on very specific ways to educate and take care of Da-song. When the Kims move into the Parks' house, Ki-woo notes that Ki-jung seems to fit in well with the trappings of wealth, and can carry off a luxurious lifestyle naturally.
Ki-taek
The patriarch of the Kim family. He has held a bunch of different jobs, working as a valet and at a bakery, but struggles to provide for his family. When he is given the opportunity to work as Mr. Park's driver, he figures out how to be the best driver he can be, and to provide some light companionship to Mr. Park. He soon discovers, however, that Mr. Park does not like his smell, and feels deflated by this insult. After their home is flooded, Ki-taek tells his son that it is best to never have a plan, since plans never work out the way one expects.
Chung-sook
Chung-sook is the matriarch of the Kim family. She is brusque and unsentimental like her daughter, toughened by life in poverty. She likes to play games with Ki-taek, calling him a cockroach and belittling him, as part of their marital dynamic.
Mrs. Park
Mrs. Park is a beautiful, wealthy, and ditzy head-of-household who prides herself on not being able to do domestic chores. Wealth has rendered her completely helpless, and she often spends her days napping on the couch or purchasing items for the house. She is very nice, but not especially deep or compassionate. She is the archetype of the mistress of a wealthy household: glamorous, naive, and good at wielding power with feminine grace.
Mr. Park
Mr. Park is the head of the Park household. He is a generally congenial but snobbish man. He is obsessed with keeping his employees controlled and hates nothing more than when one of his charges "crosses the line." He spoils his son and is rather alienated from his desires and happiness.
Moon-gwang
Moon-gwang is the Parks' first housekeeper, a holdover from the house's first owner, the architect who built it. She takes great pride in her work as a housekeeper, and loses her job unexpectedly after the Kims make her peach allergy look like active tuberculosis. She returns to the house to check on her husband, who is living in a secret subterranean bunker.
Geun-sae
Geun-sae is Moon-gwang's husband, who is living in the bunker underneath the Parks' house, hiding out from the loan sharks who want to kill him. He is a violent and desperate man, and ends up going on a killing spree after the Kims kill his wife, Moon-gwang.
