Kim Sung-kyu (born April 28, 1989), referred to as Sunggyu[1] or Sungkyu, is a South Korean singer and actor.

In November 2012, Kim began his solo career with his first extended play, Another Me, which debuted at number one on the Gaon Album Chart.

Originally intending to pursue rock music in a band, Kim instead became a trainee for the dance group Infinite, of which he would later assume the positions of leader and main vocalist.

Kim made his debut as the leader and main vocalist of South Korean boyband Infinite in 2010.

[4] In the same years, he was featured in Epik High's music video "Run" along with fellow members Woohyun, Sungyeol, L, and Sungjong.

[5] Kim and other members of Infinite dubbed the children's cartoon Wara Store from December 27, 2011 to March 27, 2012 as themselves.

In May 2012, it was announced that Kim would join Immortal Songs 2 as a fixed member alongside Super Junior's Ryeowook.

Kim also composed the lead single "60 Seconds" with Sweetune and personally participated in writing the lyrics for the track "41 Days".

In February 2013, Kim was confirmed to have made a cameo appearance in KBS's new sitcom A Bit of Love alongside four other idols, MBLAQ's G.O, KARA's Seungyeon, ZE:A's Siwan, and Secret's Ji Eun.

On January 29, 2015, Kim was confirmed to star in new KBS variety show, Fluttering India, along with Exo's Suho, CNBLUE's Jonghyun, Super Junior's Kyuhyun, TVXQ's Changmin, and SHINee's Minho.

[25] It was later reported that he'd sustained a rib injury[26] while filming the programme[27] which ultimately led to the delay of Infinite's comeback.

[28] August 2017 marked the release of "Drama" by R&B producer Primary featuring Kim,[29] which topped multiple domestic charts.

2000 tickets were sold out within 1 minute for the fan meet in Taipei,[31] which prompted organisers to add another session on the same day of November 19, 2017.

[33] The album was well received and its lead single, "True Love", garnered wins on two music shows and topped domestic chart.

On the last day of his solo concert, Kim made the surprise announcement that he is enlisting into the military on May 14, 2018.

[38] He served as an active duty soldier for the 22nd Division Infantry "Yulgok" located in the Goseong area (North Eastern part of South Korea).

[43][44] On December 14, 2020, Kim made his solo comeback with his third EP, Inside Me, and its lead single "I'm Cold".

[47] On June 14, 2021, Kim signed with DoubleH TNE, a subsidiary of NHN & MLD Entertainment, after the expiration of his contract with his former agency.

[58] In January 2023, Kim was announced as a cast of the musical "Red Book", playing the character Brown.

[61] On December 24, 2023, Kim announced his solo fan meeting 'ㅅㄱ 2' for January 27, 2024 at KBS Arena Hall.

[64] Kim held his LV3: Let's Vacay in Seoul concert on 3rd to 4th August 2024 at Jamsil Student's Gymnasium, which were sold out on both days.