Kihyun made his solo debut with the single album Voyager in March 2022,[4] in addition to having recorded numerous original soundtracks for South Korean television dramas.

[10] Along with six other trainees from the show, Monsta X was formed, a hip-hop idol group that debuted under Starship Entertainment, with the EP Trespass on May 14, 2015.

[13] In May 2015, Kihyun and fellow Monsta X member Jooheon, released an original soundtrack "Attractive Woman" for KBS2's Orange Marmalade.

[18] Kihyun sung the acoustic version of "The Tiger Moth" for the soundtrack for MBC's drama Shopping King Louie, which was released on October 27.

[32] In September, Kihyun appeared again as a contestant on King of Mask Singer's special duet episode for the 2021 Chuseok holiday.

[39] On September 16, he appeared and performed in the music festival KPOP LAND 2022, to commemorate love, peace, and a better world, in Jakarta, Indonesia.

[46] In April, he became a permanent panelist for JTBC's current affairs and liberal arts program Han Moon-cheol's Black Box Review.

[47] On April 16, Kihyun and Joohoney participated in the OST of TVING's original Our Game: LG Twins, titled "Awake".

It is a song about overcoming difficulties by cheering each other on and raising hope, which combines rock and hip hop, and contains a moving theme of turning adversity upside down.

[52] On June 22, Kihyun attended the Korea-Vietnam Cultural Exchange Night, held at Vietnam National Convention Center, as "K-pop Representative Singer".

It was a place to enjoy K-pop and V-pop together, to strengthen cultural consensus between the two countries and promote friendship for the future generations.

[57] As the main vocalist of Monsta X, Kihyun has been described to possess a soulful pop rock voice that is "refreshing yet sexy" and "does not shake even in powerful performances".

It was unfolded with various photos, cherished items, and events including the appearances of the members and their childhood, plus a special space to share precious memories with his fans to commemorate the third anniversary of Monsta X's debut.

[68] In May 2022, Kihyun became the new muse for the Korean unisex street brand AQOstudiospace's 2022 summer collection, which held various promotions, such as SNS participation and exclusive photocards events.

[64] In January 2021, he donated ₩10,000,000 to the Good Neighbors, a charity organization that helps low-income families in South Korea, which will be used for support kits containing hygiene products for girls.