After making a bit-part appearance in the 2009 film 4th Period Mystery while she was still a student at Chung-Ang University, Im landed her breakthrough role when she was cast as Dan Sa-ran, a prideful, lower-middle class dancer, in the 2011 popular television series New Tales of Gisaeng. Cast alongside Sung Hoon and Han Hye-rin, the series explored the premise that the gisaeng, the Korean equivalent of a geisha or courtesan, still existed in modern-day Korea. Im was nominated for several newcomer awards for her performance and won the SBS Drama Award for Best New Star and the Korea Drama Award for Best New Actress. That same year, she had a prominent supporting role in Paradise Ranch and made a cameo appearance in Salamander Guru and The Shadows.

To develop her range, Im increased her profile with starring roles as diverse as a feisty chairman’s daughter in I Do, I Do (2012), a cool assassin in Iris II: New Generation (2013), the calculating stepdaughter of a high official in Inspiring Generation (2014), a college dropout in Five Enough (2015) and the female antagonist in Blow Breeze (2015). In 2016, Im played the title character in the prison romance film Eunha.

In 2017, Im was cast in the leading role of a widowed policewoman in Lovers in Bloom, for which she received a KBS Drama Award for Best Actress in a Daily Drama. Also that year, she made a cameo appearance as a serial killer who pretends to be a victim in tvN’s crime procedural drama Criminal Minds, based on the American series of the same name.

In 2018, Im experienced a rise in popularity when she starred opposite Cha Eun-woo of Astro fame in the JTBC romantic comedy series Gangnam Beauty. One of the highest rated drama in Korean cable television history, it garnered praise for its portrayal of issues afflicting South Korean society, particularly on its superficial beauty standards and discrimination on the basis of physical appearance. For her performance as Kang Mi-rae, a college student who went under cosmetic surgery to evade derision from her peers, Im won the Top Excellence Award for Actress in a Drama at the 26th Korea Culture and Entertainment Awards.

In 2019, Im starred in the mystery drama Graceful Family as a bold, charismatic chaebol heiress. The series premiered with high viewership ratings for MBN network and attracted the media attention in Korea and internationally.