Shin began her career as a model for teen magazine KiKi in 1998. Since then, she became one of the most in-demand and highest paid commercial endorsers in South Korea. Notable among her forays into branded entertainment is the 2008 multi-episode Summer Days opposite Hyun Bin and Ryoo Seung-bum for LG Xnote featuring music by You Hee-yeol, as well as Friends & Love, a movie-style extended advertisement for Giordano in 2011 costarring Jung Woo-sung and So Ji-sub.
In 2009, Shin went to Milan, Italy to shoot a photo spread for Elle Korea with Calvin Klein model Jamie Dornan. In 2011, she was chosen as the first Asian model for the DIY Project ad campaign of American clothing brand Rag & bone, then was subsequently featured in The New York Times's T Magazine.
Shin appeared in several music videos for K-pop boyband g.o.d, until her acting debut in 2001 with a supporting role in popular melodrama, Beautiful Days. The newcomer quickly rose to stardom, through the high school martial arts comedy film Volcano High with Jang Hyuk, and the college romance movie Madeleine with Jo In-sung.
She then took on a supporting role in Kim Jee-woon's noir film A Bittersweet Life, reuniting her with previous co-star Lee Byung-hun. She then portrayed a deaf character in Sad Movie. This was followed by leading roles in the melodrama A Love to Kill with Rain, romantic comedy series The Beast and the Beauty with Ryoo Seung-bum, and psychological thriller The Devil with Uhm Tae-woong and Ju Ji-hoon. In the 2007 film My Mighty Princess, Shin simultaneously played two characters.
As Shin entered her mid-twenties, she began showcasing more maturity in her choice of roles. In Go Go 70s, Shin played a sexy counterculture singer and won numerous accolades for her portrayal. She then acted as an unfaithful wife in The Naked Kitchen, and a cynical young woman in search of her father in Sisters on the Road, a critically acclaimed indie film which also stars fellow actress and close friend Gong Hyo-jin. But Shin became best known for her portrayals of supernatural horror icons revamped into endearingly innocent yet spunky heroines in the rom-com My Girlfriend Is a Nine-Tailed Fox (2010), and the historical drama Arang and the Magistrate (2012).
After appearing in The X, a 2013 spy thriller short film directed by Kim Jee-woon, Shin returned to the big screen in 2014 in Gyeongju, an introspective arthouse romance opposite Park Hae-il. This was followed by romantic comedy My Love, My Bride, in which she and Jo Jung-suk played a newly married couple; it was a remake of the same-titled 1990 hit which starred Choi Jin-sil and Park Joong-hoon.
After her travels were documented on the cable channel O'live in 2008, Shin published a book titled Shin Min-a's French Diary in 2009.
She has also contributed her vocals to several singles and soundtracks.
Diva (2020) - Yi-Young
A Quiet Dream | Chunmong (2016) - Min-A (cameo)
My Love, My Bride | Naui Sarang Naui Shinboo (2014) - Mi-Young
Gyeongju (2014) - Kong Yoon-Hee (coffee shop owner)
A Million | 10 eok (2009) - Jo Yoo-Jin
Sisters on the Road | Jigeum Idaeroga Joayo (2009) - Myung-Eun
The Naked Kitchen | Kichin (2009) - Ahn Mo-Rae
Go Go 70s | Go Go 70 (2008) - Mimi
My Mighty Princess | Murim Yeodaesaeng (2008) - Kang So-Hwi
The Beast and the Beauty | Yasuwa Minyeo (2005) - Jang Hae-Joo
Sad Movie | Saedu Mubi (2005) - Ahn Soo-Eun
A Bittersweet Life | Dalkomhan Insaeng (2005) - Hee-Soo
Madeleine (2003) - Hie-Jin
Volcano High | Hwasango (2001) - Yu Chae-i
The X (2013) - X - Mi-A (X's mysterious girlfriend)
Hometown Cha-Cha-Cha | Gaetmaeul Chachacha (tvN / 2021) - Yoon Hye-Jin
Chief of Staff 2 | Bojwagwan 2: Sesangeul Woomjikineun Saramdeul (JTBC / 2019) - Kang Seon-Yeong
Chief of Staff | Bojwagwan: Sesangeul Woomjikineun Saramdeul (JTBC / 2019) - Kang Seon-Yeong
Tomorrow With You | Naeil Geudaewa (tvN / 2017) - Song Ma-Rin
Oh My Venus (KBS2 / 2015-2016) - Kang Joo-Eun
Arang and the Magistrate | Alangsattojeon (MBC / 2012) - Ah-Rang
My Girlfriend is a Nine-Tailed Fox | Nae Yeochineun Gumiho (SBS / 2010) - Mi-Ho
The Lucifer | Mawang (KBS2 / 2007) - Seo Hae-In
A Love to Kill | I Jukilnomui Sarang (KBS2 / 2005) - Cha Eun-Seok
Punch | Ddaeryeo (SBS / 2003) - Jang Yu-Bin
Beautiful Days | Areumdawoon naldeul (SBS / 2001) - Lee Min-Ji
Excellent Actress (mini series) ("Oh My Venus") - 2015 KBS Drama Awards - December 31, 2015
Best Couple Award ("Oh My Venus") - 2015 KBS Drama Awards - December 31, 2015
Best Style - 2015 (51st) BaekSang Arts Awards - May 26, 2015
Best Couple Award (Arang and the Magistrate") - 2012 MBC Drama Awards - December 30, 2012