Frei Otto (1925–2015) was a German architect and engineer renowned for his pioneering work in lightweight, tensile structures. He revolutionized sustainable, biomimetic architecture, creating designs inspired by natural forms and minimal material use. His iconic projects include the Munich Olympic Stadium (1972), the Multihalle in Mannheim, and the German Pavilion at Expo 1967. Otto’s research on adaptive, flexible structures influenced contemporary parametric design and sustainable construction techniques. Awarded the Pritzker Prize (2015), he remains a leading figure in experimental, ecologically responsive architecture, shaping the future of lightweight, adaptable building systems.