Knoll is best known for its modern, elegant furniture, which has been widely used in public spaces and commercial buildings around the world. His most famous creations include the FK chair, the 369 chair, the Vostra chair and the Berlin sofa.
Over the years, Knoll became one of the most influential designers of his time, and his furniture became collector's items for design enthusiasts and collectors alike. He died in 1945 in New York, where he had moved to open a design office.