She rose to fame with her role in the romantic comedy film My Sassy Girl (2001), which became a tremendous sensation across Asia and sparked an international breakthrough for Korean cinema.

Although she made her film debut in the little-watched White Valentine in 1999, it was not until later in the year when she was featured in a commercial for Samsung My Jet Printer that she became a popular sensation.

[13][14][15] The following year, Jun made her first well-publicized film appearance in late 2000 with Il Mare, a handsomely shot melodrama set on Ganghwa Island.

[16] The film did respectably well at the box office (despite opening on the same day as blockbuster Joint Security Area) and solidified her status as a star.

[18] Jun's breakout film was comedy My Sassy Girl, a tale of a gullible college student and his slightly unhinged girlfriend.

Jun's "sassy, loud, and domineering character while also embodying traits of a pure-hearted girl" ran contrary to gender norms in Asia.

[33] Jun's next project Daisy teamed her with Jung Woo-sung (who frequently appeared together with her in Giordano and 2% Lotte Chilsung Water advertisements), and drew attention for its 100% location shooting in the Netherlands, and for using the Hong Kong director Andrew Lau (Infernal Affairs).

[40] For the film A Man Who Was Superman, Jun cut off her signature long silky hair to play a cynical documentary producer who meets an odd, Hawaiian-shirt-clad modern-day hero who battles urban apathy and preaches the virtues of lending a hand.

"[41] In 2010, she acted opposite Chinese actress Li Bingbing in the English-language film Snow Flower and the Secret Fan, based on Lisa See's bestselling novel of the same name, which was directed by Wayne Wang (The Joy Luck Club).

[42][43][44] She was photographed by Annie Leibovitz for the July issue of the American edition of Vogue, the first Korean actress to be included in the iconic fashion magazine.

[50] Jun's success on the big screen reaffirmed her status as one of the top actresses in Korea, as well as being one of the biggest box office draw in chungmuro.

[51] 14 years after Happy Together in 1999, Jun made her highly anticipated return to television in fantasy romance My Love from the Star,[52] opposite her The Thieves co-star Kim Soo-hyun.

[57][58] In 2015, she reunited with director Choi Dong-hoon for Assassination, an espionage action film set during the 1930s colonial era in which she played a sniper who assembles a squad of independence fighters to kill a Japanese army commander and a pro-Japanese Korean business tycoon.

[65][66][67] In November 2016, Jun made her small-screen comeback in the SBS fantasy romance drama The Legend of the Blue Sea with Lee Min-ho, reuniting with My Love from the Star scriptwriter Park Ji-eun.

She was later confirmed to reprise her role and lead the series' sidequel Kingdom: Ashin of the North, alongside her Assassination co-star Park Byung-eun.

[73][74] In April 2020, Jun was confirmed to lead tvN mystery thriller drama Jirisan, written by Kingdom screenwriter Kim Eun-hee, opposite Ju Ji-hoon.

[79] She continued making donations of ₩100 million to the Hope Bridge Disaster Relief Association, to aid efforts for the COVID-19 pandemic in 2020, and to help victims of the wildfire that had started in Uljin, Gyeongbuk in 2022.

[93][94][95] In September 2022, Jun became the first South Korean female artist to become Global Ambassador for British luxury fashion house Burberry.

[100] In February 2023, Jun was named as the global face of the Burberry's first campaign under its new chief creative officer Daniel Lee along with Shygirl, Skepta, Vanessa Redgrave, Liberty Ross, Raheem Sterling and more.

[104] Jun married Choi Joon-hyuk on 13 April 2012, at Shilla Hotel in Jangchung-dong, central Seoul, with more than 600 guests, including celebrities, close friends and family attending the wedding.

[111][2] Jun along with six other Korean stars (Jung Woo-sung, Kim Sun-a, Jo In-sung, Ji Jin-hee, Cha Tae-hyun and Yang Jin-woo) sued the monthly movie magazine Screen in 2006 for commercially using their pictures without permission.

[122] In 2011, SidusHQ CEO Jung Hoon-tak was accused of illegally using Jun's bank account to pocket profits from a merger and acquisition.