Apart from his group's activities, he has established himself as a musical actor, notably through his participation in the original and Korean versions of stage musicals including The Three Musketeers, Catch Me If You Can, Moon Embracing the Sun, Singin' in the Rain, The Days, Robin Hood, Werther, Mozart!, The Man Who Laughs, Phantom, and Frankenstein.

He was also cast in television shows including Radio Star, We Got Married, Mamma Mia, Fluttering India and in the third, fourth, seventh, and eighth seasons of New Journey to the West.

Kyuhyun's mother, Kim Hanna, pursued business ventures such as establishing an art academy, as well as a guesthouse (MOM House) located in Myeongdong.

Kyuhyun also has an older sister, Ara, a violinist who studied abroad in Vienna, Austria, before returning to Korea to teach the violin.

[6] Kyuhyun made his first appearance as a part-time model of Super Junior in a news broadcast on May 23, where the group introduced their new single, U.

Later that year, Kyuhyun, alongside member Ryeowook, featured in the song "Wish" (소원) in labelmate TVXQ's repackaged edition of Mirotic.

On August 5, Kyuhyun released his third solo song "Hope, a dream that never sleeps" (희망은 잠들지 않는 꿈) for the television drama Baker King, Kim Tak Goo.

In November, Kyuhyun along with label mates TRAX's Jay, SHINee's Jonghyun, and newly debuted singer Jino (now a member of Pentagon) formed the project group SM The Ballad.

From December 15, 2010, to mid-January 2011, Kyuhyun rotated as D'Artagnan with TRAX's Jay in The Three Musketeers at Chungmu Art Hall in Seoul, where the singers co-starred with Yoo Jun-sang, Im Ki-jun, Kim Mu-yul and Dana Hong.

He also appeared on KBS's music competition program Immortal Songs 2, replacing group mate Yesung on the show.

Kyuhyun was one of four fixed MCs on Super Junior's show Foresight, and in September he replaced fellow member Heechul as an MC on MBC's Radio Star.

[13] He later appeared on We Got Married as part of Fighting Junior, supporting fellow member Leeteuk and his on-screen wife actress Kang So-ra.

In 2012, Kyuhyun was cast as Frank Abagnale Jr., rotating with Um Ki-joon, Kim Jeong-hoon, Park Gwang-hyun and Key of SHINee in the Korean production of the Broadway musical Catch Me If You Can.

[15] Later in June, Kyuhyun featured in labelmate Henry's debut solo song "Trap" alongside SHINee's Taemin.

"[17] From January 18 to February 23, 2014, Kyuhyun starred in the musical adaptation of MBC's Moon Embracing the Sun at the Seoul Arts Center, alongside Girls' Generation's Seohyun.

[18] In May, it was announced that Kyuhyun would star in the musical Singin' In The Rain as Don Lockwood, opposite Girls' Generation's Sunny.

[23] Just 12 hours after the album's online release, the title track, "At Gwanghwamun", achieved an 'all-kill' by topping all nine digital Korean charts.

[26][27] In early 2015, Kyuhyun was cast in news-based KBS reality show Fluttering India (두근두근 인도) alongside TVXQ's Changmin, Shinee's Minho, CNBLUE's Jonghyun, Infinite's Sungkyu and Exo's Suho.

[38] On August 22, SM Entertainment announced that Kyuhyun would take a break from his activities due to vocal cord nodules.

He underwent surgeries and temporarily halted his activities, including his performance in an ongoing musical that he was cast in, Mozart, as well as two weeks of recording on Radio Star.

[39] In October 2016, it was announced that popular singer Sung Si-kyung would be a participating composer in Kyuhyun's upcoming album, which was scheduled to release within the year.

[40] Kyuhyun performed the new track at his concert Reminiscence of a novelist on October 29 to 30 at Ehwa Womans University and Busan from November 5 to 6 at Bexco Auditorium.

[60] The Super Junior member also recorded a remake version of the hit 1993 song "Confession Is Not Flashy" by Lee Seung Hwan for OST Part 4 of the popular tvN drama Hospital Playlist.

[66] On August 23, 2020, Toon Studio unveiled the OST "The Moment My Heart Flinched" recorded by Kyuhyun for the webtoon She Is My Type.

[72] Kyuhyun returned with his new series 2021 Project: 季, starting with the first single "Moving On", released on January 26, 2021, representing the winter season.

[74] The second single from the 2021 Project: 季 series, titled "Coffee", was released on April 13, 2021, representing the spring season.

[88] During an appearance on SBS Power FM's "Cultwo Show" alongside Park Minsung and Choi Ji-hye, Kyuhyun revealed that he had injured his left foot during the musical.

[95] Kyuhyun, who was sitting behind the driver's seat, suffered the most serious injuries including a fractured hip, broken ribs, and facial scratches and bruises.

"[99] After fierce debate between his parents and doctors, another surgeon named Dr. Wang Youngpil suggested an alternative operation that would instead make an incision in the ribs.

In 2013, Kyuhyun and label mates Yoona, Minho, Sulli, Seohyun, and Siwon were appointed as the main models for SK Telecom.