Lee Hye-ri (born June 9, 1994), better known mononymously as Hyeri, is a South Korean actress, singer, and television personality. She rose to fame as the youngest member of girl group Girl's Day, and was named as the "Nation's Little Sister" by the South Korean media outlets after appearing as a fixed cast member on Real Men (2014). Hyeri later became known as the female lead in Reply 1988 (2015), which was the highest-rated drama in Korean cable television history at the time. After back-to-back success in variety and the small screen, Hyeri ranked third in Forbes Korea Power Celebrity list in 2016 and became one of the highest-paid commercial models in South Korea. Hyeri was a regular cast member on Amazing Saturday from 2018 until 2020 when she left the show to focus on her acting career. She has since starred in the IQIYI series My Roommate Is a Gumiho (2021) and U+ Mobile TV's Friendly Rivalry (2025).