She is best known for the films Phone (2002), Sex Is Zero (2002), Miracle on 1st Street (2007), Tidal Wave (2009), Closer to Heaven (2009), and Pawn (2020), as well as the television series Damo (2003), Something Happened in Bali (2004), Hwang Jini (2006), Secret Garden (2010–2011), The King 2 Hearts (2012), and Empress Ki (2013–2014).

[2][3] She is one of South Korea's most sought after and critically acclaimed actresses,[4][5] particularly known for her versatility in pulling off roles in various genres such as action, comedy, horror, drama, sports and medical.

In 2012, the actress revealed that she had failed over 100 auditions before her debut, "I passed my college entrance and written exams and was accepted to the department of theater and film.

"[10] Ha Ji-won made her TV debut in the 1996 teen drama, New Generation Report: Adults Don't Understand Us.

[13][12] In 2000, Ha made her film debut in the thriller, Truth Game, alongside Ahn Sung-ki, where she was chosen for the role from a pool of 1,500 prospective candidates.

[18] Later, Ha reunited with Ditto co-star Kim Ha-neul in the drama, Secret, playing an antagonist role.

The film was a huge success in South Korea and was also a hit in Italy,[24] officially dubbing her as "Asia's Horror Princess".

[7][25] Following Phone in the same year was Yoon Je-kyoon's American Pie-inspired movie, Sex Is Zero, co-starring Im Chang-jung.

[33] What Happened in Bali was a huge success, with its final episode reaching a peak rating of 39.7%,[34] and won Ha the coveted Best Actress recognition at the 40th Baeksang Arts Awards.

[42][43] The series was a huge ratings success,[44] giving rise to a boom in gisaeng-themed entertainment—musicals, TV dramas, films, even cartoons.

Proven to be a commercial success, the drama series brought in high domestic ratings and garnered much interest regarding its fashion, catchphrases and music.

[61] Ha had spent eight hours a day swimming and training with weights to get in shape for the role, obtained a scuba diving certificate and motor license in a week to "immerse" herself in character.

[65][66] As Ha had simultaneously portrayed a North and South Korean character on the small and big screen,[67] she was dubbed as "The Flower of Reunification" for crossing boundaries of the two nations.

[72] In 2014, Ha, together with Kang Ye-won and Son Ga-in of Brown Eyed Girls, then starred in the Charlie's Angels-inspired action fusion sageuk, The Huntresses.

[76] However, in contrast to her previous dramas, The Time We Were Not in Love received low ratings and Ha's performance was called into question.

[79] In 2016, Ha starred in the South Korea-China co-production film, Life Risking Romance, alongside Taiwanese actor Chen Bolin.

[84] Ha returned to the small screen with MBC's medical drama Hospital Ship, which started airing in August 2017.

[97] In 2012, Ha gave a lecture on movie production in China as part of CJ CGV's cultural exchange program Toto's Workroom.

[98] As part of her contract with fashion label Crocodile Lady, Ha launched her own "Secret Jeans" line and designed a handbag for the brand which was sold for 179,200 won ($157).

"[112][113] Ha has also played an active role in helping underprivileged and disabled children, running a donation project named Smile Again Foundation with Gangnam-gu Family Welfare Center.

During the event, both actors spent time with recovering children and received an award for their previous efforts in promoting the sharing of medical services.

[117] In 2015, Ha, fashion icon Ko So-young, and figure skater Yuna Kim designed bags in cooperation with the Italian luxury brand Fendi.

As Operation Smile's Ambassador, Ha decided to donate the proceeds from the bag she designed to Operation Smile, a NGO that performs cleft lip and cleft palate surgery and delivers postoperative and ongoing medical therapies to children in low and middle income countries.