Nation's Little Sister () or Nation's Little Brother () is an informal title in South Korean entertainment industry. It refers to "a young female [or male] celebrity in her [or his] late teens to early twenties... [who is] cute, bright, and innocent."

People associated with the title Nation's Little Sister Im Ye-jin (born 1959), actress Lee Sang-ah (born 1972), actress Lee Jae-eun (born 1980), actress and singer Jang Na-ra (born 1981), singer and actress Yoon Eun-hye (born 1984), singer and actress Moon Geun-young (born 1987), actress and model Park Bo-young (born 1990), actress Park Shin-hye (born 1990), actress and singer Yuna Kim (born 1990), figure skater Ahn So-hee (born 1992), actress and singer Kim Ji-won (born 1992), actress and model IU (born 1993), singer-songwriter and actress Son Yeon-jae (born 1994), rhythmic gymnast Lee Hye-ri (born 1994), actress and singer Kim Hye-yoon (born 1996), actress Kim So-hyun (born 1999), actress Kim You-jung (born 1999), actress Kim Sae-ron (2000–2025), actress Shin Eun-soo (born 2002), actress Lee Won-hee (born 2007), singer

Nation's Little Brother Lee Seung-gi (born 1987), singer, actor and host Kim Sung-cheol (born 1991), actor Park Bo-gum (born 1993), actor Yoo Seung-ho (born 1993), actor Yeo Jin-goo (born 1997), actor

Other usages People's Little Sister (Korean: 국민 여동생) is a song by South Korean girl group Sonamoo from their debut extended play, Deja Vu.

See also Nation's First Love

References