Kim Hye-song (Korean: 김혜성; Korean pronunciation: [kim.ɦe.sʌŋ] or [kim] [he.sʌŋ]; born 9 March 1993) is a North Korean long-distance runner. Marathoner Kim Hye-gyong is her sister. They are fraternal twins. Hye-song is the eldest of the two. According to their coach, Jong Myong-chol, Hye-song is more conservative and quiet than her sister. The coach considers their healthy rivalry in races and friendship a key to their success. Kim represents the . Together she and her sister train five times a week, running 25–30 km (16–19 mi) a day.