John Kim was a Human male who lived in South Carolina on Earth together with his wife Mary. In 2349, John and Mary celebrated the birth of their only son, Harry Kim, whom they loved very much. (VOY: "Eye of the Needle", "One", "Favorite Son", "Author, Author") John Kim had at least one nephew, Dennis Kim. (VOY: "Repression") He was also tone deaf, according to Harry. (VOY: "Favorite Son")
In 2355, John and Mary took a six year old Harry to a haunted house. (VOY: "Collective")
In 2358, the Kims participated in a humanitarian mission to a colony that had just suffered from a radiation disaster. (VOY: "The Thaw")
In 2371, Quark suggested to Harry Kim that his father might like Lobi crystals as cufflinks. (VOY: "Caretaker")
In 2378, he and his wife were able to establish contact with their son who had been lost in the Delta Quadrant aboard the USS Voyager. (VOY: "Author, Author")
When Voyager discovered what they believed to be a nebula populated with several wormholes, later determined to be a Borg transwarp hub, Harry hoped that one lead to the Alpha Quadrant, to which Tom Paris poked at Harry, "[w]ho knows, Harry, it might take us right into your parents' living room." (VOY: "Endgame")
John Kim was played by actor Robert Ito.
His name comes from the "Author, Author" script.
According to the Star Trek Encyclopedia, 4th ed., vol. 1, p. 416, John Kim was a Starfleet officer who worked at Starfleet Command on Earth.