2008–2010 In 2008, Ratchanok entered the international circuit at the age of 13. The first international tournament she played was the
Laos International series, in which she played both singles and doubles. She lost the singles final to Vietnam's
Lê Ngọc Nguyên Nhung. She won her first individual international title in 2009 by winning the
Vietnam International Challenge when she was 14. She made history by becoming the youngest-ever champion at the
2009 World Junior Championships at 14 in Malaysia by beating her compatriot
Porntip Buranaprasertsuk. She reached the final of the
Malaysia International Challenge 2009, losing out to
Sapsiree Taerattanachai. She also reached the
2009 SEA Games women's singles final, but lost to her compatriot
Salakjit Ponsana. Her successful run continued after she won the
Smiling Fish International, beating teammate
Rawinda Prajongjai. She won back-to-back Grand Prix tournaments by winning the
Vietnam Open Grand Prix beating China's
Zhou Hui and the
Indonesia Grand Prix Gold after defeating
Cheng Shao-chieh from Chinese Taipei. In the
2010 Guangzhou Asian Games, she won a silver medal as a member of the women's team. In the final, she lost to
Wang Xin, at that time world number 1.
2011–2012 Ratchanok participated in
BWF World Championships and lost in the third round to eventual winner
Wang Yihan. She was a finalist at the
Chinese Taipei Open, where she was defeated by
Sung Ji-hyun. She became the most successful player ever in individual events at the
World Junior Championships, winning the girls' singles title for the third straight time by defeating Indonesia's Elyzabeth Purwaningtyas. She won the
India Open Grand Prix Gold where she received a walkover against Porntip Buranaprasertsuk in final. She was also a member of the women's team that defeated Indonesia in the final of the
2011 SEA Games. She herself was a bronze medalist in
singles event, where she lost in the semi-finals to Singapore's
Fu Mingtian. In 2012, Ratchanok, at 16 years of age, was awarded the Best Female Athlete Award in Thailand after winning the world junior title for three successive years. She reached the finals of the
Thailand Open but lost to
Saina Nehwal. After defeating the higher-seeded
Juliane Schenk of Germany in round of 16, she reached the quarter-finals of the
2012 Olympic Games where she lost to second seed Wang Xin despite leading 21–17 and 16–9 in the second game. She entered the finals of a Superseries tournament for the first time in the
China Open but lost to
Li Xuerui 12–21, 9–21. She qualified for the
2012 BWF Superseries Finals and won all of her group matches in straight games against Juliane Schenk,
Tine Baun and Saina Nehwal. She lost in the semi-finals there to
Wang Shixian. She finished the year as world number 9.
2013 Ratchanok reached the finals of the
All England Open, losing to
Tine Rasmussen 14–21, 21–16, 10–21. She is the youngest ever singles finalist at the All England Open. She lost in the final of the
Swiss Open Grand Prix Gold after being defeated by Wang Shixian. She won her first Superseries tournament by beating
Juliane Schenk 22–20, 21–14 in the
India Open to become the youngest-ever Superseries winner at the age of 18 years, 2 months and 22 days (she held this record for 6 months until
Akane Yamaguchi won the
2013 Japan Super Series at the age of 16). She again reached the finals of the
Thailand Open, winning the title after beating
Busanan Ongbamrungphan to become the first Thai ever to win the women's singles title at the Thailand Open since it was first held in 1984. Ratchanok withdrew from both the Indonesia and Singapore Opens to recover from a foot injury and prepare for the BWF World Championships. In
World Championships in August, she was seeded fourth. She reached the quarter-finals of this tournament for the first time, where she defeated
Carolina Marín in a very hard-fought encounter. Her semi-finals path was relatively easy, where she won against
P. V. Sindhu in two games. In the final, she won the title, beating world number 1 and Olympic gold medalist Li Xuerui 22–20, 18–21, 21–14. She was the first-ever Thai player to be the World Champion and was also the youngest singles World Champion ever at the age of 18. She became the world champion while still being eligible to play in the World Junior Championships that year. After the World Championships, she injured her back and failed to qualify for the
Super Series Finals, finishing the year as the world number three. She was awarded the "2013 Best Females Athletes Award" from the Thailand Sports Authority.
2014 In 2014, Ratchanok reached the final of the
Korea Open for the first time, meeting
Wang Yihan and continuing her losing streak against Wang. She was awarded "Best Asian Sporting Icon" by
Fox Sports Asia, based on voting from internet fans on its website. She reached the finals of the
Indonesia Open but lost to
Li Xuerui. She failed to defend her
World Championships title after losing in the third round to
Minatsu Mitani. She was defeated by
Bae Yeon-ju in the quarter-finals of the
2014 Asian Games. She qualified for the
Superseries Finals in Dubai but failed to pass the round-robin stage after losing group matches against
Tai Tzu-ying and Akane Yamaguchi. She finished the 2014 year as world number 6.
2015 In 2015, Ratchanok made a comeback by reaching the final of the
India Open for the second time but lost to her opponent
Saina Nehwal. A month later, she became the first Thai singles player to win the
Asia Championships by defeating Li Xuerui in the final 20–22, 23–21, 21–12 in China. It was the first time that Ratchanok had beaten Li since the final of the 2013 World Championships. In June, she won her first Superseries Premier title by beating
Yui Hashimoto of Japan in straight games at the
Indonesia Open. However, at the
BWF World Championships, she had to retire from court when 8–5 up in the decider against
Lindaweni Fanetri in the round of 16 from cramps. Ratchanok won a gold medal with the Thailand women's team at the
2015 SEA Games in Singapore. After the Indonesia Open, she did not reach the final of any tournaments but earned enough points to qualify for the
Dubai World Superseries Finals. In the group stage, she lost to Wang Yihan, but won two other matches against Wang Shixian and Sung Ji-hyun, progressing to the semi-finals. She lost to Wang Yihan there, which brought their head-to-head record to 0–12. She finished the 2015 season at world number seven.
2016 In 2016, Ratchanok won the
Thailand Masters, a second Grand Prix Gold tournament in Thailand, by beating
Sun Yu in the final. She won the
India Open for the second time by beating Li Xuerui in the final. In the
Malaysia Open the week after, she defeated Wang Yihan for the first time by beating her in the semi-final. In the final, she beat Tai Tzu-ying to earn the Malaysia Open title for the first time. This was the first time she had won two consecutive Superseries tournaments; Ratchanok then became the first singles player to win three Superseries in three consecutive weeks by winning the
Singapore Super Series, defeating Sun Yu in the final. By winning three Superseries in a row, she also rose to the number 1 spot in the world rankings, becoming the first Thai to achieve this feat. Her winning streak ended after she lost to
Sayaka Sato in the
Asian Championships. Ratchanok qualified for the
2016 Summer Olympics and was the
Thai flag bearer. At the Olympics she failed to pass the round of 16, losing to Akane Yamaguchi, in two games: 19–21, 16–21. After the Olympics, she suffered a knee injury which forced her to retire from subsequent tournaments. In the
Superseries Finals, Ratchanok lost in straight games to Sung Ji-hyun and Tai Tzu-ying, and retired injured against
He Bingjiao. She finished 2016 at a world ranking of five.
2017 Ratchanok played in her first tournament of 2017 in March, the
All England Open. She made her way to the quarter-finals, where she faced off against world no. 2 Carolina Marín. She won after being down 11–18 in the rubber set but won 10 straight points to close out the match. After defeating Akane Yamaguchi in the semi-finals, she was defeated by Tai Tzu-ying 16–21, 20–22. Ratchanok later in the year took the
Thailand Open title, beating compatriot
Busanan Ongbamrungphan in the final. She also won the
New Zealand Open beating
Saena Kawakami. She was disappointed in the
World Championships when she lost to
Chen Yufei in the quarter-finals. After defeating Sung Ji-hyun and Tai Tzu-ying in the
Denmark Open, Ratchanok beat Akane Yamaguchi in the final in three games after being 16–19 down in the final game; she won the game 21–19. She said that she dedicated the title to Thailand's king,
Bhumibol Adulyadej, who had died the year before. She qualified for the season-ending
Superseries Finals, where she defeated Sung Ji-hyun and Tai Tzu-ying and lost the third group match to Chen Yufei. She was defeated in the semi-finals by Akane Yamaguchi in three games after she was leading in the final game.
2018 At the beginning of the year, Ratchanok won the
Malaysia Masters Super 500, beating Tai Tzu-ying in the finals, winning 24–22 in the third set. In the
World Championships, she lost to
Saina Nehwal in the third round. At the
Asian Games, Ratchanok made it to the quarter-final stage before losing out to Nehwal. She made the finals of the
Hong Kong Open, losing to
Nozomi Okuhara. She qualified for the
BWF World Tour Finals, where she ended her losing streak against
Chen Yufei. She lost to Nozomi Okuhara but defeated Canada's
Michelle Li to secure a semi-finals spot. She lost in the semi-finals to eventual gold medalist
P. V. Sindhu. She finished the year at world no. 8.
2019 - 2020 In 2019, Ratchanok won the
Malaysia Masters Super 500, defending her title by winning in straight games for all her matches, including the final where she beat Carolina Marín. At the final of
German Open Super 300, she lost to Akane Yamaguchi in three games, losing 23–25 in the deciding game. She then won her third
India Open title by beating
He Bingjiao. This was Ratchanok's first victory over her. She lost the final of
Thailand Open to
Chen Yufei in two games. She won the bronze medal at
Basel World Championship after losing to Nozomi Okuhara in the semi-finals. Ratchanok was one point away from winning the
Korea Open against He Bingjiao, but she saved four match points and won the next game. Ratchanok failed an out-of-competition drug test in April but was not banned by the BWF. The BWF statement reads: "The ethics hearing panel determined Ms. Ratchanok Intanon committed an anti-doping rule violation, but as the athlete was able to demonstrate that her adverse analytical finding was related to the ingestion of meat contaminated with clenbuterol, she was found to bear no fault or negligence for the violation, and thus no period of ineligibility has been imposed on her." She lost again to Chen Yufei in the final of the
Hong Kong Open. She participated in the
World Tour Finals, where she beat
Busanan Ongbamrungphan, lost to Tai Tzu-ying, and lost to Nozomi Okuhara in the last group match. Ratchanok's first title of 2020 came when she won the
Indonesia Masters title by beating Carolina Marín in three game.
2021–present For 2021 season, Ratchanok managed to reach one final in
Indonesia Open where she lost to
An Se-young in the finals. Ratchanok also manage to qualify for
2020 Olympics which she excelled in the group stage but got knocked out at the round of 16 to Tai Tzu-ying in three sets of 21–14, 18–21, 18–21. The next year, Indonesia proved to be her strong domain as she excelled to the final again, this time in
Indonesia Masters. In the final, she fought in a grueling three games match where she ended up losing to
Chen Yufei. She manage to avenge this lost with a win against Chen in
Malaysia Open with another grueling three sets between them in the process to the title. In July 2023, Ratchanok advanced to her next final in
Canada Open after one year and a half drought in which she lost to
Akane Yamaguchi. Three months later in September, Ratchanok was scheduled to compete at the
Hangzhou 2022 Asian Games. She withdrew from the competition and the rest of the 2023 tour due to the ankle injury she suffered in the
Hong Kong Open. After a 3-month hiatus, Ratchanok returned to the international tour at the
Malaysia Open in January 2024. She then won the
Spain Masters in March. Ratchanok competed for the fourth time at the Olympics in the
2024 Paris, but again failed to win a medal after losing in the quarter-finals to
Gregoria Mariska Tunjung. In October, she finished as a finalist at the
Arctic Open. In 2025, Ratchanok started the year with a good performance by winning
Indonesia Masters against a young player from South Korea,
Sim Yu-jin. Ratchanok won her second title late in the year when she beat Gregoria Mariska Tunjung, who were in the final for
Japan Masters for three straight years, in straight games. In SEA games, Ratchanok was an instrumental piece for the women's team seventh straight gold medal triumph. She also gained her first individual gold medal in the women's singles, beating her compatriot,
Supanida Katethong in the final. == Honors and awards ==