Kim Yo-han joined the Mnet idol competition program Produce X 101 in May 2019, where he finished in first place. This earned him a spot in the show’s derivative boy group X1, which debuted with the single Flash in August 2019. However, the group disbanded only months later following the vote manipulation scandal that hit Mnet reality competition programs Produce 101 and Idol School. In August 2020, Kim Yo-han released his solo digital song titled No More. In October of that year, he debuted with the South Korean boy group WEi with the mini-album Identify: First Sight. In January 2022, he dropped his first solo extended play called Illusion.
Kim Yo-han made his acting debut as the male lead in the Korean adaptation of the hit Chinese series A Love So Beautiful. He then starred in the KBS2 youth drama School 2021, which won him Best New Actor at the KBS Drama Awards.
Kim Yo-han was a national taekwondo athlete prior to his foray into the entertainment industry.