Born in September 1987, Kim Yo-jong is the youngest daughter of late leader Kim Jong-il and is thought to be the most important figure in the tyrannical regime after Kim Jong-un. She is the only one of his siblings considered a close, trusted and powerful ally and is seen by his side almost constantly during his meetings with world leaders
Kim shares the same mother as Kim Jong-un and Kim Jong-chol, the brother who is thought to be not very senior in the political power system. She spent her early years at her mother's Ch’angkwang Hill residence in central Pyongyang with her two older brothers. Between 1996 and 2000, Kim studied in Switzerland. She began attending Liebefeld Hessgut public school and later was joined by Kim Jong-un at Liebefeld-Steinhölzli public school, the two enrolled under pseudonyms. School officials in Switzerland have said she was over-protected by the coterie of guards and caretakers - she once reportedly had a mild cold and was immediately pulled from school and taken to hospital. Although they lived with an aunt and uncle, the time abroad was said to be an isolating experience and the siblings depended on each other for company and support. It is believed she went on to further her education at the Kim Il-sung Military University and then computer science at the Kim Il-sung university.
Appointed a junior cadre to the WKP in 2007, Kim Yo-jong reportedly was involved in succession plans after Kim Jong-il suffered a pair of strokes the following year and took on an increasing role as her father's secretariat until his death in December 2011. She was very rarely seen in public until 2010, but became prominent in the lead up to her father's death.
Under her brother's rule, Kim became acting director of the National Defense Commission before earning her appointment as First Deputy Director of the Workers Party's Propaganda and Agitation Department in late 2014 - a role she is thought to still hold and where she works on her brother's public image in the country. For her leadership role in the Propaganda and Agitation Department, Kim was among the seven North Koreans sanctioned by the U.S. Treasury in early 2017 for "serious human rights abuses and censorship activities." That means US citizens are prohibited from conducting any transactions with her. Any property and assets in the US would be frozen. She was made a member of the politburo, the party's most senior ruling committee, in 2017, giving her even greater power including over state security, and was voted to the Supreme People's Assembly as a representative for the Killimgil district in the 2019 parliamentary election.
Kim Yo-jong first gained international attention in 2018, when she was the first member of the North Korean ruling family to visit the southern country since the end of the Korean War in 1953. She was part of the delegation to the Winter Olympics, where North and South competed as a joint team. The 2018 thaw which followed saw her working alongside her brother as he set off on an international diplomacy path, meeting South Korean President Moon Jae-in, China's Xi Jinping and most importantly accompanying her brother to his historic, high-profile denuclearisation talks with President Trump, the first held in Singapore in June 2018 and the second in Hanoi, Vietnam, in February 2019. After Donald Trump scrapped denuclearisation talks, Kim Jong-un reportedly blamed his sister for the failure and demoted her in 2019, before reinstating to the party’s powerful politburo.
Not much is known about her personal life, but in early 2015, it was reported that Kim Yo-jong had married the son of Choe Ryong, the powerful party secretary and Kim Jong-un's second in command. She was reported to be pregnant in spring 2015, and again around the time of the 2018 Winter Olympics.
The close relationship with her brother and her increasingly senior roles in the political apparatus put her once again in focus in April 2020 during a period when Kim Jong-un seemed unusually long absent from any public events. Speculation that he was unwell or even dead put her among the top ranks to take on his mantle, though the country has never had a female leader.