Lee Ra-yoon (; born Im Yoo-kyung on November 5, 1992), known professionally as Lee Da-in () is a South Korean actress.
Lee and her older sister Lee Yu-bi are the daughters of actress Kyeon Mi-ri. Their stepfather, Lee Hong-heon, adopted the sisters after marrying Kyeon in 1998. After her mother's remarriage, Lee changed her name from Im Yoo-kyung to Lee Joo-hee. Lee changed her real name, Lee Joo-hee to Lee Ra-yoon ahead of her marriage. But she did not change her stage name.
Lee has been in a relationship with actor Lee Seung-gi since late 2020. On February 7, 2023, Lee Seung-gi announced their engagement in letters posted on his social media accounts. They married on April 7, 2023, at the Grand Intercontinental Seoul Parnas in presence of friends and family.
On November 1, 2023, her agency confirmed that Lee is pregnant with her first child, and is due to give birth in February 2024. Lee gave birth to their first child, a daughter, on February 5.