Jin Kwon and Sun Kwon are two of the main protagonists of Lost, and thus their family is central to the series and its stories.
- Jin-Soo Kwon - The son of a fisherman who married the daughter of a rich business man.
- Sun-Hwa Kwon - The daughter of a rich business man who married the son of a fisherman.
- Mr. Kwon - Jin's father who raised him alone when Jin's mother left.
- Jin's mother - An unnamed woman and mother of Jin who was well known to be a "slut".
- Woo-Jung Paik - Sun's father who is a ruthless businessman.
- Mrs. Paik - Sun's mother who tried to set her on a date with Jae Lee.
- Ji Yeon Kwon - Jin and Sun's daughter who stayed with her grandmother when Sun left to find Jin.
- Soo - Sun's aunt who blessed her at her and Jin's wedding.
- Jae Lee - Sun's secret love affair who committed suicide when he thought Jin found out.
- Bpo Bpo - Jin and Sun's Shar Pei pet dog.