[7] Although his parents allowed him to sign a contract with SM Entertainment, they did not give him any help because they wanted him to take responsibility for his actions.

[12] Not long after Choi's first television appearance, SM Entertainment released an announcement that he would debut as one of the twelve members in a boy band.

A few months before the debut of Super Junior 05, Choi made his first media appearance with bandmate Han Geng as one of the runway models in a fashion show by Bum Suk.

Choi debuted as part of 12-member rotational project group Super Junior 05 on November 6, 2005, on SBS' music program Popular Songs, performing their first single, "Twins (Knock Out)".

Following the addition of thirteenth member Kyuhyun, the group dropped the suffix "05" and became officially credited as Super Junior.

[14] In 2006, Choi was cast in the Hong Kong epic film A Battle of Wits, playing the role of the Liang Prince.

[19] The same year, he starred in the big-budget spy series Athena: Goddess of War, a spin-off to the 2009 hit drama Iris.

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.

[33] In 2015, Choi Siwon with EnterMedia Pictures (CEO Lee Dong Hoon) purchased the rights to the 2011 Daum webtoon Interview, authored by Rude Vico.

[34][35] In October 2017, Choi starred in the tvN's youth romance drama Revolutionary Love alongside Kang So-ra.

[42] In 2021, Choi starred in the TVING web series Work Later, Drink Now and made a cameo appearance in the movie New Year Blues.

[45] In 2022, Choi starred in the ENA romantic comedy series Love Is for Suckers and returned for the second season of Work Later, Drink Now.

[53] Upon his release from the military, Choi confirmed to volunteer for a UNICEF campaign in Vietnam from August 21 to 25, 2017, alongside fellow labelmate Jaemin of NCT Dream.

The campaign is named as "SMile for U" which is a music education programme for children with disabilities conducted in partnership with Choi's agency.

[55] In 2008, Choi and his fellow Super Junior-M members appeared on Chinese postage stamps, becoming the first South Korean artists to do so.

The stamps were sold at a charity event to raise funds for victims of an earthquake which happened in China earlier that year.

[67][68] In 2007, when being asked about male actors portraying sexually ambiguous roles as in The King and the Clown (2005), Choi said: "I will respectfully refuse any such offers.

While I respect all genders, I do not wish to acknowledge homosexuals as I have been taught that God created Man and Woman with specific characteristics and duties.

"[69][70] On September 11, 2015, Choi retweeted theologian John Piper who stated "Obergefell is not constitutional; so-called same-sex marriage does not exist."

Choi also shared Piper's link to an article in support of Kim Davis, as well as two Biblical passages, confirming he remained against gay marriage.

The controversial meme shows a scene from the movie Titanic (1997) in which actor Billy Zane's character Caledon Hockley is trying to be rescued but is told "women and children first."

[72][73][74] On September 30, 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.