Yoon So Yi debuted as a model in Graffiti Magazine in 2001. After a few years of print and commercial modelling, she auditioned for Ryu Seung Wan’s action-comedy Arahan in 2004. Based on a popular South Korean comic, Arahan explored the consequences of unleashing an ancient evil spirit into a modern city, with Yoon’s character part of a hidden school of ancient masters who train a naive young policeman to fight this evil force. Yoon underwent strict training for six months in a film action school, where she had to overcome her phobia of heights. The film was a relative commercial success, with one review describing her as “tall and attractive in an excellently non-cutesy way”. She received a Best New Actress nomination at the 2004 Blue Dragon Film Awards.
Yoon next starred in the TV drama Say You Love Me, a dark, twisted love story between four people. This led to a friendship with her co-star Kim Rae Won, with whom she starred in a series of advertisements for Samsung Digital Plaza. When Kim later launched his own management company Bless Entertainment, she would also join his stable of stars.
After playing Jung Joon Ho’s love interest in The Twins, Yoon was cast in Shadowless Sword, a wuxia martial arts epic set in ancient China. In the role of a beautiful young swordswoman who protects the future king, Yoon says that she was inspired by Anita Mui in The Heroic Trio and that the strong-willed female character appealed to her. She learned wushu for three months in Korea, then wire action from the Chinese stunt team.
In 2006, she became part of the ensemble cast of Goodbye Solo, written by renowned drama writer Noh Hee Kyung. Even though her dramas do not attract a high number of viewers, Noh has gained a cult following for her in-depth portrayal of ordinary characters, taking a more human natural approach through realistic and yet emotional lines. Goodbye Solo featured seven characters of different generations and backgrounds, as they reflect on human relationships and nature. Yoon would later work again with mostly the same crew in the 2-episode TV special Several Questions That Make Us Happy.
Goodbye Solo’s writer Noh and veteran actress Bae Jong Ok introduced Yoon to Join Together Society (JTS), a Seoul-based Buddhist international relief agency (Yoon herself is a Buddhist). Since then she has been extremely active in charity work for JTS, spearheading street fund drives and various programs to benefit underprivileged children in North Korea and developing countries.
An athlete in junior high, Yoon was a Sports Model major at Dongduk Women’s University, but eventually dropped out due to showbiz commitments. She later enrolled in Dongguk University as a Theatre and Film major, slowing down her acting activities to focus on her studies and becoming known in the Korean press as one of the very few celebrity model students. Yoon graduated in 2011.
Her next project, Auction House, attempted a different format from the standard serialized Korean drama. The twelve-episode season 1 had four directors and four writers, airing one episode every week, with each director producing his own segment in his own style, crossing genres. The episodic format was not a hit with Korean audiences (despite a season 2 focusing on plastic surgeons with a completely different cast).
Yoon played a former reporter struggling to adjust to life as a chaebol daughter-in-law in Glass Castle; the drama was a modest success. In 2009, she was cast as a last-minute replacement leading lady in the quirky Hero starring Lee Jun Ki. Despite being praised as a well-acted and solid drama, Hero received low ratings. Yoon’s next film Try to Remember, about lovers in the past whose love transcends time and brings them together in the present day, premiered at the Puchon International Fantastic Film Festival.
In 2011 she starred in a specially commissioned 20-minute film for the Gyeongju World Culture Expo. Titled Byeongnucheon (“The Bracelet of Blue Tears”), the fantasy adventure aims to spearhead Korea’s nascent stereoscopic film industry and combines live-action sequences with 3D animated computer graphics.
Yoon recently joined the microblogging site Twitter with the handle “soy00”.
She also starred in the fusion sageuk Warrior Baek Dong Soo.