1996–2004: Six-time European Youth champion Muzychuk had a long stretch of success at the
European Youth Chess Championships, medalling in nine consecutive years from 1996 at age six to 2004 at age fourteen, including six gold medals. the under-12 girls' division in 2002, and the under-14 girls' division twice in 2003 and 2004. She won three silver medals at the tournament, two in the under-10 girls' division in 1997 and 1999 behind
Nana Dzagnidze and
Silvia-Raluca Sgîrcea respectively, and one in the under-12 girls' division in 2001 behind
Iozefina Păuleţ. At the national level, Muzychuk won the Ukrainian girls' national youth and junior championships three times, once each at the under-10 level in 2000, the under-12 level in 2002, and the under-20 level in 2004. On the global stage, Muzychuk also medalled in the girls' divisions of the
World Youth Championships, earning a bronze medal at the under-10 level in 2000 behind
Tan Zhongyi and
Harika Dronavalli, as well as two silver medals, one at the under-12 level in 2002 behind Tan and another at the under-14 level in 2004 behind Dronavalli. Muzychuk was awarded the titles of
Woman FIDE Master (WFM) in 2001 and
Woman International Master (WIM) in 2002. She earned her first
FIDE rating of 2197 in July 2001 at age 11. She first participated at the
European Individual Women's Championship in 2002 at age 12, and finished with at least an even score in her first three appearances through 2004. Her performance at the 2003 edition as well as a joint first-place finish at the 17-round Lviv's Hopes tournament later in the year helped Muzychuk reach a rating of 2300 by October 2003. She also earned a sufficient number of
Woman Grandmaster (WGM)
norms at these two tournaments, and was formally awarded the WGM title in 2004. At the end of June 2004, Muzychuk switched federations to Slovenia. Her 2004 European Youth gold and World Youth silver medals were among her earliest triumphs with Slovenia. She then had a significant rise in rating towards the end of the year to reach a rating of 2400 for January 2006. Having already reached a rating of 2400, Muzychuk earned all of her
International Master (IM) norms in 2006 and 2007, the first two of which as a double norm at the
Women's Chess Olympiad in Turin and the last of which in the Serbian Women's League. She was awarded the IM title in 2007. One of her other best results in classical chess during these years was at the 2006 European Individual Women's Championship, where she scored 7½/11 and finished in equal third place. In
fast chess, Muzychuk won the 2007 European Women's
Blitz Chess Championship and finished second in the European Women's
Rapid Chess Championship. Muzychuk first participated in the
Women's World Chess Championship knockout tournament in 2008. As the 11th seed out of 64 competitors, she won her first round match against
Maria Velcheva before being upset by 22nd seed Dronavalli in the second round in rapid tiebreaks. Over the next two years, Muzychuk first reached a rating of 2500 and then earned her first two GM norms. The first was a seven-game norm at the European Club Cup for Women in 2008. The second was a full nine-round norm at the InventiChess round robin tournament in 2009, where she had an even score against opponents with a much higher average rating of 2618, including six Grandmasters rated above 2600. During the latter event, she defeated
David Howell, a GM rated 2624. She came close to another GM norm in Group B at the round robin
Corus chess tournament in
Wijk aan Zee in 2010, but fell just short with a performance rating of 2580 by virtue of scoring 5½/13 against opponents with average rating of 2637. Although she could not complete the norm, she was the only player to defeat the winner of the tournament,
Anish Giri. That summer, Muzychuk had her biggest triumph of the year by winning the
World Junior Chess Championship for under-20 girls in
Chotowa, Poland, finishing in clear first with a score of 11/13. She ended 2010 by reaching the third round of the
Women's World Chess Championship, where as the 7th seed she was upset by 10th seed
Ju Wenjun.
2011–2012: Grandmaster title at age 21, 2600 rating Muzychuk completed the requirements for the Grandmaster title in 2011 with her third and fourth GM norms to reach the 27-game norm minimum needed. She earned a nine-game norm in the opening event of the
2011–12 FIDE Women's Grand Prix in
Rostov with a score of 5½/9, narrowly missing a norm over the full 11 games that would have been sufficient for reaching the 27-game minimum. She reached that minimum with her fourth GM norm at the
European Women's Team Chess Championships, where she scored a near-perfect 8½/9, including 6½/7 against her seven highest-rated opponents to complete the norm and earn the Grandmaster title at age 21. With this performance, her rating also rose to 2580. Muzychuk continued to perform well in the Grand Prix, finishing in joint first with
Koneru Humpy at the Kazan event. During the event, she became the fourth woman to reach a rating of 2600 after
Judit Polgár, Koneru, and
Hou Yifan. Following the tournament, she reached a career-best ranking of No. 197 in the world in August and also became the second-highest-rated woman for the first time, only behind Polgár. Nonetheless, in the final standings for the overall Grand Prix, Muzychuk finished in third place behind Koneru and the winner Hou, losing out on the winner's right to challenge for the Women's World Championship. Later in the year, Muzychuk took part in the unrated
ACP Golden Classic classical tournament in Amsterdam that followed an unusual format where games were
adjourned if not completed in 40 moves. She finished with an even score, and notably defeated
Krishnan Sasikiran, a Grandmaster rated 2707 at the time. At the end of the year, Muzychuk was the 3rd seed at the
Women's World Chess Championship, but was upset in the second round by the 30th seed and eventual winner
Anna Ushenina in rapid tiebreaks.
2013–2016: World Rapid and World Blitz champion Muzychuk again generally finished towards the top of the standings in the
2013–14 FIDE Women's Grand Prix events, but did not win any of them and ultimately finished fourth in the overall standings. She had a better result at the
Tata Steel Challengers tournament in Wijk aan Zee in early 2014, where she came in fourth place with a score of 8/13, corresponding to a performance rating of 2666. With this performance, her rating rose back to 2583. After the tournament, however, her rating fell back into the mid-2500s and would not reach 2570 again until 2017 three years later. The championship brought her blitz rating to a career-best 2665. The World Blitz victory was her last major triumph with Slovenia. In May 2014, Muzychuk switched federations again back to her home country of Ukraine. She stated her sister continuing to play for Ukraine as well as the new federation president Viktor Kapustin as reasons for her return. At the end of the year, she entered the Ukrainian women's national championship for the first time since she was the 2003 champion and again won the tournament. Muzychuk was less active in 2015. One of her highlights of the year was the
Women's World Championship, where she had her best result to date. As the third seed, she reached the quarterfinals. She knocked out 62nd seed
Amina Mezioud, 30th seed
Aleksandra Goryachkina, and 19th seed
Lela Javakhishvili without any tiebreaks before being upset by 11th seed
Pia Cramling in the second set of rapid tiebreaks. The tournament was ultimately won by her sister Mariya, whom she stayed to support. Early in 2016, Muzychuk won the women's first prize at the
Gibraltar Chess Festival with a score of 7/10, corresponding to a performance rating of 2677. During the tournament, she defeated two Grandmasters rated above 2600,
Salem Saleh and
Laurent Fressinet, the latter of whom was rated 2700 and is the only player she has defeated in a rated classical game with a rating of at least 2700. At the end of 2016, Muzychuk won both the Women's World Rapid Championship and the Women's World Blitz Championship in
Doha, thereby also defending the latter of these two titles from 2014. She became the third player to win both events in the same year after
Susan Polgar in 1992 and
Magnus Carlsen in 2014.
2017–2018: World Championship runner-up Muzychuk came closest to winning the classical
Women's World Chess Championship in 2017 in Tehran, where she finished runner-up to Tan Zhongyi. As the 2nd seed, she reached the final without needing tiebreaks, notably defeating 34th seed
Alina Kashlinskaya, 7th seed
Antoaneta Stefanova, and 3rd seed Alexandra Kosteniuk. Unlike the other matches which were best-of-two classical games, the final match against the 9th seed Tan was played as a best-of-four classical games. After Muzychuk lost the second game with the black pieces, she won the third game with the white pieces, sending the match to tiebreaks as the other two games ended in draws. Tan won the second game of the rapid tiebreaks to clinch the title. At the end of 2017, Muzychuk gained widespread media attention for her decision to boycott the World Rapid and Blitz Championships in Saudi Arabia and forgo the opportunity to defend both of her World Championship titles because of Saudi Arabia's
restrictions against women, including those related to women's clothing and the prohibition on women going outside without being
accompanied by a man. She refused to attend despite the tournament having a prize fund five times higher than the previous edition. She commented: Her announcement of the preceding comments on
Facebook was shared over 74,000 times and received over 165,000 reactions predominantly in support of her statement. The following year in 2018, Saudi Arabia was scheduled to host the tournament again; however, it was moved to Russia less than a month in advance largely due to a separate issue of Israeli players being denied visas needed to compete. Muzychuk returned to the tournament and fared better in the rapid event than the blitz event, finishing in fourth place. For the second consecutive
Women's World Championship knockout tournament, Muzychuk faced Stefanova and Kosteniuk in back-to-back rounds, this time as the 4th seed in 2018. Although she once again defeated the 13th seed Stefanova, she then lost to the 5th seed Kosteniuk in the quarterfinals in rapid tiebreaks.
2019–present: Three Candidates tournaments at the 2020 Gibraltar Chess Festival After the 2018 World Championship, the Women's World Championship switched to a match format where the reigning champion would defend their title against the winner of an eight-player
double round-robin Candidates tournament, the first of which would take place in 2019. Muzychuk was one of the players who qualified for the Candidates tournament by rating. Although she had a strong finish, she could not overcome a slow start where she lost two of the first three games to Dzagnidze and Tan, and her final score of 8/14 only sufficed for second place. At the end of 2019, Muzychuk won a third medal at the World Blitz Championship, earning the silver medal a ½ point behind only Lagno. Muzychuk began 2020 at the
Gibraltar Chess Festival. Although she did not win the women's prize, she was awarded the overall tournament brilliancy prize for her last-round game against
Ori Kobo, an Israeli Grandmaster. She was still able to qualify for the Candidates tournament by reaching the semifinals of the inaugural
Women's World Cup in 2021, a tournament that replaced the World Championship knockout events. As the 4th seed, she defeated 20th seed
Elisabeth Pähtz and 5th seed Dzagnidze among others before losing to 1st seed Aleksandra Goryachkina in the penultimate round. Although she also lost the third place match to 7th seed Tan, she still earned one of three Candidates spots awarded through the World Cup by virtue of Goryachkina having already qualified as the previous World Championship runner-up. Muzychuk ended the year at the World Rapid and Blitz Championships. She finished in the top 15 at both events but was not in contention to medal by the later rounds. In 2024 Muzychuk participated in
Candidates Tournament, finishing 8th. Muzychuk finished 3rd in overall standings of
FIDE Women's Grand Prix 2024–25 with a tie for first with
Zhu Jiner in both Stage 4 Cyprus and Stage 6 Austria. In 2025 Muzychuk won the Women's section of
Norway Chess 2025. She qualified to the
Women's Candidates Tournament 2026 on 22nd March 2026 as
Koneru Humpy withdrew the tournament citing the
2026 Iran war; Muzychuk qualified by the FIDE Women's events leaderboard 2025. Muzychuk finished 5th in the
Women's Candidates Tournament 2026 she was in sole lead after 7 rounds but lost her 8th round gane to
Divya Deshmukh then drew 5 of the remaining 6 games losing to
Bibisara Assaubayeva in round 13 finishing with the score 7/14. ==Team competitions==