The Kwan Um School of Zen (관음선종회,觀音禪宗會) (KUSZ) is an international school of zen centers and groups founded in 1983 by Zen Master Seung Sahn. The school's international head temple is located at the Providence Zen Center in Cumberland, Rhode Island, which was founded in 1972 shortly after Seung Sahn first came to the United States. The Kwan Um style of Buddhist practice combines ritual common both to Korean Buddhism as well as Rinzai school of Zen, and their morning and evening services include elements of Huayan and Pure Land Buddhism. While the Kwan Um Zen School comes under the banner of the Jogye Order of Korean Seon, the school has been adapted by Seung Sahn to the needs of Westerners. According to James Ishmael Ford, the Kwan Um School of Zen is the largest Zen school in the Western world.

Seungsahn Haengwon, born Duk-In Lee, was a Korean Seon master of the Jogye Order and founder of the international Kwan Um School of Zen. He was the seventy-eighth Patriarch in his lineage. As one of the early Korean Zen masters to settle in the United States, he opened many temples and practice groups across the globe. He was known for his charismatic style and direct presentation of Zen, which was well tailored for the Western audience.