Lim YoonA (임윤아) is a South Korean singer, dancer, actress, and member of GIRLS' GENERATION (소녀시대 also known as SNSD). She graduated from Daeyoung High School and later obtained a bachelor's degree in Theater from Dongguk University.

Before debuting, she had already been through many auditions to appear in music videos and dramas. She joined SM Entertainment (SM엔터테인먼트) in 2002 when she was cast in the SM Saturday Open Casting Audition and spent five years as a trainee. She was introduced to the public through various appearances in music videos and commercials, first appearing in TVXQ's "Magic Castle" music video in 2004.