Marcel Lajos Breuer (May 21, 1902 – July 1, 1981) was a Hungarian-born American modernist architect and furniture designer. He was a leading figure of the Bauhaus and the International Style, and the pioneer of tubular steel furniture in modern design. Born in Pécs, Hungary, Breuer studied at the Vienna Academy of Fine Arts before enrolling at the Bauhaus in Weimar, Germany in 1921. He later became a teacher and head of the Bauhaus furniture workshop. Inspired by bicycle handlebars, he created the iconic Wassily Chair (Model B3) in 1925, the world’s first mass-produced tubular steel chair, which revolutionized modern furniture design.

In 1937, Breuer moved to the United States and taught at Harvard Graduate School of Design, spreading Bauhaus ideas across American residential architecture with Walter Gropius. He settled in New York in 1946 and ran his own architectural practice, focusing on large public buildings. His major works include UNESCO Headquarters in Paris, Whitney Museum of American Art in New York, De Bijenkorf Department Store in Rotterdam and IBM Research Center in France.

His design philosophy centered on functionalism, innovative materials and simple geometric forms, combining industrial technology with human scale. His works spanned furniture, housing and public architecture, exerting a profound influence on 20th-century modern architecture and industrial design. He received the AIA Gold Medal in 1968, retired in 1977, and passed away in New York in 1981.