She first rose to stardom through her role as the young Eun-suh in the hugely popular television drama series Autumn in My Heart (2000), followed by a well-received turn in Kim Jee-woon's critically acclaimed horror film A Tale of Two Sisters (2003).

At age 21, she became the youngest recipient of a Grand Prize ("Daesang") which she won at SBS Drama Awards for the television series Painter of the Wind (2008).

[5] Moon's rise to fame came in 2000 when she starred as the younger counterpart of Song Hye-kyo's character in the pan-Asia hit drama Autumn in My Heart.

[13][14] In 2005, Moon starred in Innocent Steps where she played the role of an ethnic Korean living in China, who finds herself to be a complete fish out of water after moving to South Korea.

[21] Shin was a real-life historical figure, a painter who lived during the Joseon Dynasty (1392–1910) and was known for his realistic and delicate depictions of daily life.

[23] In 2010, Moon starred in Cinderella's Sister, a modern fairy tale retelling of the contentious relationship between two stepsisters (opposite Seo Woo).

[31] She then starred in Goddess of Fire (2013), playing Yoo Jung, a character based on Baek Pa-sun, the first female potter and porcelain artist of the Joseon Dynasty.

[33] Moon made her long-awaited return to the big screen in Lee Joon-ik's period film The Throne, in which she played Lady Hyegyeong, the wife of Crown Prince Sado.

Moon made the contributions secretly through her mother, Ryu Seon-young, but her good deeds became known when Morning Reading revealed its 2007 account information online.

Moon donated about ₩300 million in 2006 to a learning center for poor children in Haenam County, South Jeolla Province, near her hometown of Gwangju.

Moon donated more than ₩850 million over the last ten years to the Community Chest of Korea, a nationwide network of 16 nonprofit fundraising organizations, becoming the biggest individual donor.

[55] In April 2009, Moon donated the Haenam Children's Center to be used as a study room for poor students to the NGO group Good People, an international charity group of UN UCOSCO special consultative status aiming to improve self-sustainability and eradicate extreme poverty through restoration of self-esteem using the principles of human dignity and equality at a global level.