Kahn's father, a rabbi, brought his family to the United States in 1881. Kahn had little schooling but was taken on as a student by George D. Mason, a leading Michigan architect. Following this apprenticeship, Kahn traveled for a year in Europe on a scholarship won in a competition sponsored by American Architect magazine. After working with various Detroit architects, Kahn established his own firm (1902), which developed into one of the largest in architectural history. In 1904 he was given his first commission for an auto factory by the Packard Motor Car Company. Kahn's design, using a reinforced concrete frame, represented an innovative departure from traditional masonry factory construction and helped establish his reputation. In subsequent structures, he originated the prototypical modern factory building, a rapidly and inexpensively built steel-frame structure that has an unobstructed floor plan and large windows and skylights and in which all production takes place under one roof and on one floor.

Kahn was the principal architect for most of the large American automobile companies for 30 years. His firm designed more than a thousand projects for Ford (Ford Motor Company), among them the fabrication and assembly plant in River Rouge, Mich., one of the largest industrial complexes in the world. By 1937 his firm was producing 19 percent of all architect-designed industrial buildings in the United States. Commissions for factories, foundries, and warehouses came from all continents. In 1929 the Soviet government asked Kahn to construct a tractor factory in Stalingrad (1930). Kahn's firm subsequently designed 521 factories in the U.S.S.R. and trained more than a thousand Soviet engineers during the 1930s.