Yu Nam-sung (born 3 October 1978) is a retired South Korean javelin thrower.
He won the 1997 Asian Junior Championships, [1] and became South Korean champion once—in 1999—before Park Jae-Myong started a lengthy winning streak. [2] He finished fifth at the 1998 Asian Games and twelfth at the 1999 Summer Universiade.[ citation needed ] He also competed at the 1999 World Championships without reaching the final. [3]
His personal best time was 79.84 metres, achieved in April 1998 in Youngju. [3]