Go Ah-sung is a South Korean actress. She began her career as a child actress, notably in The Host. Her other notable works include Snowpiercer (2013), Samjin Company English Class (2020), as well as the TV dramas Master of Study (2010) and Heard It Through the Grapevine (2015).

The Host is a 2006 South Korean epic monster film directed and co-written by Bong Joon-ho. Starring Song Kang-ho, Byun Hee-bong, Park Hae-il, Bae Doona and Go Ah-sung, it tells the story of a monster that kidnaps a man's daughter, and his attempts to rescue her.