Arwut Chinnapasaen (Thai: อาวุธ ชินนภาแสน; born December 3, 1980; nickname: 'X') is a Thai former swimmer, who specialized in sprint freestyle events. He claimed two gold medals in the 50 m freestyle at the Southeast Asian Games (2003 and 2005), before losing out to Daniel Coakley of the Philippines in 2007. Chinnapasaen is currently Head of Aquatics at St Andrews International School Bangkok. He has been a swimming coach at St Andrews since August 2015.