1. Lee Yeon-hee is most known for her work in the television series East of Eden, Phantom, Miss Korea, The Package ; and in the films A Millionaire's First Love, M and Detective K: Secret of the Lost Island.

1. Lee Yeon-hee is most known for her work in the television series East of Eden, Phantom, Miss Korea, The Package ; and in the films A Millionaire's First Love, M and Detective K: Secret of the Lost Island.
In 2002, Lee Yeon-hee successfully signed a contract with SM after she won the category of "Best Feature" in the SM Entertainment Best Youth contest.
Lee Yeon-hee had her first major role in television in MBC's mini-series One Fine Day.
In 2007, Lee Yeon-hee starred in romance melodrama A Millionaire's First Love alongside Hyun Bin.
Lee Yeon-hee made her singing debut for the film, singing "Do-Re-Mi" from The Sound of Music and Insa for the film's original soundtrack.
Lee Yeon-hee followed this with moderately successful film, M alongside Kang Dong-won; and starred alongside So Ji-sub in the short film, U-Turn.
Lee Yeon-hee returned to film, starring in Hello, Schoolgirl opposite Yoo Ji-tae.
In 2012, Lee Yeon-hee reunited with U-Turn co-star So Ji-sub in the crime thriller Phantom.
In 2013, Lee Yeon-hee made a special appearance in the historical drama Gu Family Book, where she received compliments for her improvement in acting.
Lee Yeon-hee next starred in romantic comedy film Marriage Blue, which tells the story of an engaged couple who experience last-minute jitters and cold feet just a week before their wedding ceremony.
Lee Yeon-hee closed the year with television series Miss Korea to positive reviews, with many considering her role as her best performance to date.
Lee Yeon-hee further challenged herself with a provocative role as the mysterious and seductive Japanese geisha Hisako in the historical comedy Detective K: Secret of the Lost Island in 2015.
Lee Yeon-hee then starred in MBC's 54th anniversary drama, Splendid Politics.
In 2017, Lee Yeon-hee starred in SBS's fantasy romance drama Reunited Worlds alongside Yeo Jin-goo.
Lee Yeon-hee then starred in JYP Entertainment's travel romance drama The Package opposite Jung Yong-hwa, and was complimented for her performance as a tour guide.
In 2020, Lee Yeon-hee starred in mystery drama The Game: Towards Zero, reuniting with Ok Taec-yeon with whom she starred in the 2013 film Marriage Blue.
In 2020, Lee Yeon-hee signed a contract with Vast Entertainment after her contract with SM expired.
In January 2024, Lee Yeon-hee signed with new agency Saram Entertainment after her contract with Vast Entertainment expired.
On June 2,2020, Lee Yeon-hee married her non-celebrity boyfriend in a private ceremony.
On June 7,2024, Lee Yeon-hee announced that she was pregnant after four years of marriage.