O Seyeong (, born May 2, 1942) is a South Korean poet, critic, educator, and professor at Seoul National University. He has been awarded the Korean Poets’ Association Prize, the Nokwon Literary Award, the Cheong Chi-Yong Literature Prize, the Pyun-Woon Literary Prize, the Gong Cho Literary Award, and the Manhae Literature Prize in Poetry. Life O Seyeong was born in Yeonggwang County, South Jeolla Province in 1942. He graduated from Seoul National University, and became a high school language teacher. He started his literary career in 1968 by publishing in the literary magazine Hyundae Munhak. In 1970 he published his first poetry collection, Rebelling Light (). In 1972 he was published in the literary magazine Hyundae Poetry. In 1974 he was appointed as a full-time lecturer at Chungnam National University, and graduated with a doctorate degree in Korean literature from Seoul National University in 1980. In 1982 he participated in the inaugural assembly of the Asian Poets’ Association. In 1983 he published two collections of essays, The Lyrical Truth () and Modern Poetry and Its Practical Criticism (). In 1987 O Seyeong was awarded the inaugural Sowol Poetry Prize, and was accepted into the IOWA International Writing Program. In 1994 he participated in the writing of a volume on literature as part of the Korean Studies Book Series, Lectures on Korean Literature, published by Story Brook University's Center for Korean Studies. In the same year he became a full professor at Seoul National University. He was a guest lecturer at the University of California, Berkeley in 1995, discussing Korean literature for the Department of East Asian Languages. He was awarded the Manhae Literature Prize in 2000, and published translated versions of two of his poetry collections in Germany. O Seyeong participated in the Berkeley Art Museum's 2006 poetry festival, Speak Pacific: 100 Years of Modern Korean Poetry, sponsored by U.C. Berkeley's Department of East Asian Languages. O Seyeong's volume Night-Sky Checkerboard was translated into English in 2016, published in the United States and listed by the Chicago Review of Books as one of the twelve best poetry collections of 2016. Writing O Seyeong's early works contained significant amounts of "deconstructive" poetry, leading him to be classified as a modernist poet. However, he did not simply stay fixed on linguistic experiments. He gradually became fascinated with Eastern philosophies, and based on that, he worked on lyrical depiction of humanity's existential agony.