Lee Yoo-young debuted as an actress in the 2014 film Late Spring, which won her Best Actress at the 14th Milan International Film Festival. She also bagged Best New Actress trophies at the 6th KOFRA Film Awards, the 24th Buil Film Awards, and the 52nd Grand Bell Awards for her performance in the movie. In 2015, she starred in the period drama film The Treacherous, in which she was named Best New Actress at the 36th Blue Dragon Film Awards. In 2018, she headlined the SBS legal drama Your Honor, opposite Yoon Shi-yoon. She took home the Best New Actress honors at the SBS Drama Awards for her work in the series. In 2019, she acted alongside Choi Siwon and Kim Min-jung in KBS2 drama My Fellow Citizens, which scored her several acting award nominations.
Lee Yoo-young was in a relationship with her Yourself and Yours co-star Kim Joo-hyuk until his demise in late 2017 in a car crash.