Choi was born in Seoul, South Korea, on 7 April 1986. He has one younger sister, Ji-won. His father was the former CEO of Boryung Medicine, a pharmaceutical company.

He later moved into dormitories with fellow trainees and was trained in areas of singing, acting, dancing as well as languages. He was featured in a music video of The Grace’s Dana whilst he was being trained as a solo singer in 2003. A year after, Choi made a brief appearance in family drama, Precious Family and again in 2005 in the KBS romance comedy drama Eighteen, Twenty-Nine as young Kang Bong-man, while in 2006 he played the supporting role of Park Sang-woo in romance melodrama Spring Waltz.

Choi debuted as part of 12-member rotational project group Super Junior 05 on 6 November 2005 on SBS’ music program Popular Songs, performing their first single, “Twins (Knock Out)”. Their debut album Twins was released a month later on 5 December 2005 and debuted at number three on the monthly MIAK K-pop album charts.

In March 2006, SM Entertainment began to recruit new members for the next Super Junior generation. However, plans changed and the company declared a halt in forming future Super Junior generations. Following the addition of thirteenth member Kyuhyun, the group dropped the suffix “05” and became officially credited as Super Junior. The re-polished group’s first CD single “U” was released on 7 June 2006, which was their most successful single until the release of “Sorry, Sorry” in March 2009, which helped them achieve global success.

In 2006, Choi was cast in the Hong Kong epic film A Battle of Wits, playing the role of the Liang Prince. This also marks his film debut. Choi received praise from co-star Andy Lau, who stated that Choi sets a good example for Hong Kong actors.

Choi graduated from Apgu Jeong High School in February 2006 and from Inha University in February 2012 alongside fellow member Kim Ryeowook.

In 2007, Choi starred in Attack on the Pin-Up Boys along with other Super Junior members. The same year, he was cast in MBC’s two-episode mini series Legend of Hyang Dan.

In April 2008, Choi was put into seven-member sub-group Super Junior-M, a Mandopop subgroup of Super Junior for the Chinese music industry. They debuted in China at the 8th Annual Music Chart Awards, simultaneously with the release of their first music video, “U” on 8 April 2008. This was followed by the release of the debut Chinese-language studio album, Me in selected provinces in China on 23 April and 2 May in Taiwan.

In 2008, Choi appeared on Chinese postage stamps, one of the first four South Korean artists to do so. The stamps were sold as a charity event to raise funds for victims of an earthquake which happened in China earlier that year.

In 2011, Choi headlined KBS’ action drama Poseidon. The same year, he starred in his first taiwanese drama Skip Beat! with Ivy Chen and fellow band member Donghae. The series is a live-action adaptation of Japanese shōjo manga titled Skip Beat! by Yoshiki Nakamura.

In 2012, Choi starred in SBS’ comedy satire drama The King of Dramas, based around Korean television production. He plays Kang Hyun-min, a top celebrity with a prickly personality.

Choi starred in multiple projects in 2015. He co-starred in Hong Kong historical-action film Dragon Blade with Jackie Chan, crime thriller Helios and sports drama To the Fore alongside Eddie Peng and Shawn Dou. He also starred in the Chinese romance drama Fall In Love With You Again and was cast in Billion Dollar Heir, a Chinese adaptation of the 2013 hit drama The Heirs. Back in Korea, Choi starred as the second male lead in MBC’s romantic comedy She Was Pretty. He received critical acclaim for his acting performance and comedic portrayal of the character, and experienced a rise in popularity. He released a single for the drama titled “Only You”, which ranked atop the music charts.

Choi enlisted as a conscripted policeman on 19 November 2015. He was discharged from mandatory military service on 18 August 2017.

A wax figure of Choi was unveiled at Madame Tussauds in Hong Kong on 19 November 2015.

Choi has joined many UNICEF campaigns since 2010. He was appointed as the special representative of the South Korea committee for UNICEF on 12 November 2015.

In October 2017, Choi started in the tvN’s youth romance drama Revolutionary Love alongside Kang So-ra. This marked his first project after releasing from his mandatory military enlistment on 18 August 2017.

On 30 September 2017, an untied French bulldog owned by Choi’s family bit their neighbor, 53-year-old businesswoman Kim who ran Hanilkwan, an upscale Korean cuisine restaurant. This resulted in the death of the victim six days after the incident. The cause was identified as sepsis, brought on by the bite. Choi and his father separately wrote letters of apology on their Instagram accounts on 21 October 2017. Although a family member of the deceased told media that the family were not willing to take any legal action, the Choi family received severe backlash from the public for not taking any precautionary measures with their dog.

In April 2019, Choi starred in KBS’s crime comedy drama My Fellow Citizens!.