Park first appeared internationally in January 2010 at the Junior World Championships in Taipei . There he won the bronze medal in the all-around and over 1000 m and the gold medal in the 1500 m superfinal and with the relay. At the Junior World Championships in Melbourne in 2012 , he won the gold medal four times. The following year he won bronze over 1500 m, silver over 1000 m and gold over 500 m at the Junior World Championships in Warsaw , in all-around, in the 1500 m superfinal and with the relay. At the beginning of the 2013/14 season he started in Shanghai for the first time in the World Cup. He finished 12th over 500 m, sixth over 1000 m and third place with the relay. At the following World Cup in Seoul , he achieved his first individual podium finishes with third places over 500 m and over 1000 m. In Kolomna he came back on the podium with third place in the relay and reached sixth place in the overall World Cup over 500 m at the end of the season. At the 2014 Winter Olympics in Sochi , he achieved 14th place over 500 m, 13th place over 1500 m and seventh place with the relay. In March 2014, at the 2014 World Championships in Montreal, he won the bronze medal in the 1000 m and 1500 m, and the silver medal with the relay. After finishing second over 1000 m at the World Cup in Salt Lake City at the beginning of the 2014/15 season , he took his first World Cup victories in Montreal over 1500 m and with the relay. In the further course of the season he came third in the 1500 m in Seoul and second in Dresden . He finished the season in fourth place in the overall World Cup over 1500 m. In February 2015 he won gold over 1000 m and over 1500 m at the Winter Universiade 2015 in Granada . At the 2015 World Championships in Moscow , he won over 3000 m and in the all-around event the silver medal and over 1000 m the gold medal. The following season he came in second and twice in third place in the World Cup. At the last World Cup of the season in Dordrecht , he took his third World Cup victory over 1500 m and thus achieved fifth place in the overall World Cup over 1500 m. At the season highlight, the 2016 World Championships in Seoul, he won the 1500 m and the bronze medal with the relay and the silver medal over 3000 m. In the following year he won the bronze medal over 500 m, the silver medal with the relay and the gold medal over 1500 m at the Winter Asian Games in Sapporo . In November 2017, he finished second with the relay at the World Cup in Shanghai.
His sister Park Seung-hi is an Olympic champion in the short track.
Park Se-yeong in the Sports-Reference database (English; archived from the original )
Note: This article places the family name before the person's first name. This is the usual order in Korean. Park is the family name here, Se-yeong is the first name.