Korean native Okkyung Lee began her career as an experimental cellist with classical training, eventually expanding into fields of improvisation, noise, jazz, and extended technique. Lee has collaborated with many of the bigger names in the noise and experimental improvisation scenes, including performances and recording dates with standout artists like Nels Cline, Ikue Mori, Laurie Anderson, and John Zorn. While solo releases such as Ghil (2013) capture the chaotic aggression of her performances, she has also composed more delicate, reflective chamber works such as 2020's Yeo-Neun.

Originally from South Korea, Lee moved to Boston in 1993. She attended the Berklee College of Music, where she graduated with a dual bachelor's degree in Contemporary Writing & Production and Film Scoring in 1998, then earned a master's degree in Contemporary Improvisation from the New England Conservatory of Music in 2000. She relocated to New York City and began recording and performing with a wide variety of improvisers, composers, and rock groups, including Assif Tsahar, Butch Morris, and Raz Mesinai (Badawi). Her first album, Nihm, was released by John Zorn's Tzadik in 2005; featured musicians included Ikue Mori, Trevor Dunn, and Sylvie Courvoisier. She also collaborated with experimental turntablist Christian Marclay on a split album with Italian improv duo My Cat Is an Alien. Lee's solo LP I Saw the Ghost of an Unknown Soul and It Said... appeared on Thurston Moore's Ecstatic Peace! in 2008.

In 2010, Lee received a Foundation for Contemporary Arts Grant, which allowed her to tour and collaborate with musicians abroad. She released the Tzadik-issued Noisy Love Songs and worked with artists such as Phil Minton, Evan Parker, and Anla Courtis. In 2013, her abrasive solo album Ghil, recorded by Lasse Marhaug and edited down from hours of improvisations, was released by Stephen O'Malley's Ideologic Organ imprint. Lee also worked with Marhaug and C. Spencer Yeh on the Software-issued Wake Up Awesome. Additionally, she curated the 27th edition of the Music Unlimited Festival in Wels, Austria, with the tagline "The Most Beautiful Noise in the World." Subsequent collaborations with artists such as Mark Fell, Chris Corsano, and Bill Orcutt were released.

Lee was granted a Doris Duke Performing Artist Award in 2015. She held residencies at Civitella Ranieri in Umbria, Italy, and Akademie Schloss Solitude in Stuttgart, Germany, and toured with Swans in 2016. Amalgam, a further collaboration with Marclay, was released by Northern Spy that year. Lee issued several albums in 2018: Dahl-Tah-Ghi (Pica Disk) was recorded live at the Emanuel Vigelang Mausoleum in Oslo in 2013. The Tzadik-issued Cheol-Kkot-Sae (Steel.Flower.Bird) is a long-form collaborative piece combining noise and improvisation with Korean traditional music. The Air Around Her is a collaboration with drone artist and long-string instrument master Ellen Fullman, and Speckled Stones and Dissonant Green Dots incorporates computer-generated and analog synthesizer sounds.

In 2020, Shelter Press issued Lee's chamber quartet work Yeo-Neun, which became one of her most acclaimed releases. Lee's piece "Teum (The Silvery Slit)" appeared on a split-LP with Hecker, issued by Portraits GRM in 2021. ~ Paul Simpson & Fred Thomas, Rovi