Woo-hyun debuted with Infinite on June 9, 2010 with the extended play First Invasion. In July 2011, they released their first studio album titled Over the Top, which won the Disc Bonsang Award at the 26th Golden Disc Awards. In June 2013, they released their Japanese debut studio album Koi ni Ochiru Toki in two different editions. In early 2014, Woo-hyun was launched as one half of the duo ToHeart with Shinee’s Key. They dropped their debut mini album Delicious in March of that year. In May 2016, he debuted as a solo artist with the extended play Write..

Woo-hyun made his musical theater debut in 2012 with Gwanghwamun Sonata. That same year, he appeared in the MBC series The Thousandth Man. In 2014, he starred along with Kim Sae-ron and his bandmate Sung-yeol in the KBS2 coming-of-age drama High School: Love On.

Woo-hyun enlisted as a public service worker for his mandatory military service in October 2019. He was discharged in August 2021.