Choi Won-young began his acting career in the 2002 gross out comedy film Sex Is Zero. He then landed his first TV role in an episode of the KBS2 program Drama City in 2006. In 2009, he was cast in the top-rating MBC sageuk series Queen Seon-deok. In 2011, Choi Won-young became part of the main cast of the SBS daily drama While You Were Sleeping. In 2013, he headlined the low-budget crime thriller film Your Time Is Up. The movie premiered at the 17th Busan International Film Festival. In 2017, he took home the Best Supporting Actor trophy at the KBS Drama Awards for his work in the sageuk drama Hwarang and the action series Mad Dog. In 2018, he landed a role in the hit JTBC dark comedy series SKY Castle. Aside from its high ratings, the drama also garnered various accolades, including four at the 55th Baeksang Arts Awards. In 2019, Choi Won-young received an Excellence Award at the KBS Drama Awards for his performance in the medical series Doctor Prisoner.

On February 28, 2014, Choi Won-young married actress Shim Yi-young. The two met while filming the 2013 MBC drama A Hundred Year Legacy, where they played husband and wife. They have two daughters.