1. Lee Sung-yeol, known mononymously as Sungyeol, is a South Korean singer and actor.

1. Lee Sung-yeol, known mononymously as Sungyeol, is a South Korean singer and actor.
Lee Sung-yeol was born on August 27,1991, in Suji-gu, Yongin, Gyeonggi-do.
Lee Sung-yeol has a younger brother named Lee Dae-yeol, who was signed with Woollim Entertainment and was a member and leader of the boy group Golden Child which debuted in August 2017.
On February 15,2013, Lee graduated from Daekyeung University, majoring in Applied Music with fellow Infinite members Sung-kyu, L, Dong-woo and Hoya.
Lee Sung-yeol originally planned to debut as an actor, and was once an actor trainee under SM Academy.
On June 9,2010, Lee Sung-yeol made his debut as a vocalist of Infinite with their first EP, First Invasion.
Lee Sung-yeol made his acting debut in 2011 with the drama While You Were Sleeping.
On October 21,2013, Lee Sung-yeol was cast as a main character in the web drama Love for Ten: Generation of Youth with 4Minute's Son Ji-hyun.
On May 22,2015, Lee Sung-yeol was confirmed to be in the cast of JTBC's D-Day.
In 2017, Lee Sung-yeol was cast as the male lead in a one-act drama called Temporary Cold Case Task Force, with rookie actress Lee Sung-yeol Ye Hyun.
In 2019, Lee Sung-yeol starred in the horror film 0.0MHz alongside Apink's Eun-ji, based on the webtoon with the same name.
Lee Sung-yeol enlisted as part of his mandatory military service as an active duty soldier on March 26,2019.
Lee Sung-yeol was released early on October 4,2020, due to COVID-19 precautions, and was officially discharged on October 27,2020.
On March 31,2021, Lee Sung-yeol departed from Woollim Entertainment after his contract expired.