She starred in television series Yellow Handkerchief and Terms of Endearment early in her career, and became a sought-after model in commercials.

Her projects in 2012 were hugely successful, with her period drama Moon Embracing the Sun topping the TV ratings chart, and her film Architecture 101 becoming a box office hit.

[4][5] On December 22, 2000, while attending high school, Han participated in KBS1 quiz show Challenge Golden Bell and reached the 34th stage.

[6] As a high school student, Han Ga-in appeared on KBS's TV show called The Golden Bell Challenge (도전!

She subsequently appeared in a supporting role in the popular daily drama Yellow Handkerchief and made her big-screen debut in Once Upon a Time in High School.

[15] In Bad Guy, she attempted to transform her image as a pure and innocent girl to a materialistic woman who dreams of climbing the social ladder at the expense of others.

This was followed by a leading role in romantic film Architecture 101, which got rave reviews and set a new box-office record as the highest-grossing Korean melodrama.

[30] In April 2022, she made a guest appearance in KBS2 reality-variety show 2 Days & 1 Night, in which her husband Yeon Jung-hoon is a fixed cast member.