Kim Seong-eun

At the 2013 Kagawa Marugame race she was two seconds off her half marathon best and a new marathon best followed shortly after at the Seoul International Marathon, where she was fourth overall and the first Korean with her run of 2:27:20 hours.

Her marathon performances were enough to gain a place on the team for the 2011 World Championships in Athletics, which was hosted on home soil in Daegu. There she came 28th in the championship marathon, Korea's best performer from their five-woman team. She ended the year with a 10,000 metres win at the Korean National Sports Festival, setting a personal best of 33:46.61 minutes. A fourth-place finish in 2:29:53 hours at the 2012 Seoul International Marathon earned her a spot on the Olympic marathon team. At the 2012 London Olympics she placed 96th in the Olympic marathon with a time of 2:46:38.

Kim turned away from track running from 2009 onwards and focused on road running events instead. She attempted a marathon debut at the 2009 Seoul International Marathon but failed to finish the distance. She placed tenth in the half marathon at the Summer Universiade, and then came runner-up to Lee Sun-young at the JoongAng Seoul Marathon with a time of 2:37:30 hours. She only competed in two major competitions in 2010 but performed well: she ran a personal best of 71:34 at the Kagawa Marugame Half Marathon and improved her marathon best to 2:29:27 at the Seoul International race, coming fifth.

Kim Seong-eun (Korean: 김성은 ; born 24 February 1989 in Seoul) is a South Korean long-distance runner who competes in marathon races. She represented her country at the 2012 Summer Olympics and the 2011 World Championships in Athletics. Her personal best for the marathon is 2:27:20 hours, set in 2013.