Han Ga-in (born Kim Hyun-joo on February 25, 1982) is a South Korean actress. 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.

Han Ga-in attended Seoul Gusan Elementary School (서울구산초등학교), Sunjung Middle School (선정중학교) and Baehwa Girls' High School (배화여자고등학교). On 22 December 2000, while attending high school, Han Ga-in participated in KBS1 "Challenge Golden Bell" and showed off her ability to go up to the 34th stage. It is the skill of a high school student who scored 384 points out of 400 points on CSAT.

As a high school student, Han Ga-in appeared on KBS's TV show called The Golden Bell Challenge (도전! 골든벨) and was also captured in footage of interviews with other students. Entertainment bigwigs spotted her in the news clip and immediately went to her school to offer her a part. She debuted in an Asiana Airlines commercial in 2002, and was cast in the KBS2 drama Sunshine Hunting. She subsequently appeared in Yellow Handkerchief and made her big-screen debut in Once Upon a Time in High School. In 2004, she took on the leading role in Terms of Endearment and won an Excellence award at the KBS Drama Awards.

In 2005, Han acted in Super Rookie, a satire on Korea's corporate culture and unemployment among the country's younger generation. It drew solid viewership ratings in the 20% range, and won Han the Excellence Award at the MBC Drama Awards. The drama was also reportedly well-received by Japanese viewers and contributed to Han's popularity in the country. This was followed by leading roles in Dr. Kkang and Witch Yoo Hee.

After Witch Yoo Hee wrapped in 2007, Han publicly criticized the director and writers for the drama's poor quality. She went on a three-year hiatus afterwards, merely starring in advertisements. While she soon became one of the most sought-after faces in the TV commercial industry, Han struggled to overcome her image as strictly a pretty face rather than a serious actress. Over the past decade of drama appearances, the popular actress repeatedly played familiar characters and her performances failed to wow audiences.

Mainly categorized as a "CF star," Han wanted to change that misconception with her comeback in 2010. 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.

2012 was the most successful year of Han's career yet. She first starred in period drama, Moon Embracing the Sun, in which she played the heroine, an amnesiac noblewoman-turned-shaman. The drama not only ranked number one in its time slot throughout its run but achieved a peak recorded viewer rating of 42.2 percent, thereby earning the "national drama" status. This was followed up with 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.

Han was managed by J. One Plus Entertainment from 2009 to 2011, and when her contract expired, she signed with Lee Byung-hun's agency, BH Entertainment in December 2012.

In 2018, Han returned to the small screen after six years with mystery thriller Mistress.

Han married actor Yeon Jung-hoon on April 26, 2005; they previously starred together on the 2003 TV series Yellow Handkerchief. Han had a miscarriage in 2014, and later gave birth to a daughter on April 13, 2016. On May 13, 2019, she gave birth to a son.