Guo Yonghuai, or Yung-huai Kuo (Chinese: 郭永怀; April 4, 1909 – December 5, 1968) was an expert in aerodynamics of China.
Guo was born in Rongcheng County, Shandong Province, and graduated from the department of physics of Peking University in 1935. He enrolled in an oversea program in 1939 and entered the University of Toronto in Canada in 1940 and obtained a master's degree there. From 1941 to 1945, Guo studied compressible hydrodynamics at Caltech. After obtaining the Ph.D degree, he stayed there as a research fellow. From 1946, he became an associate professor and later, professor at Cornell University. Invited by Tsien Hsue-shen, Guo returned to China in October 1956 and became the vice director of the Institute of Mechanics of the Chinese Academy of Sciences (CAS).
Guo was a founder of mechanics in mainland China and made significant contributions to mechanics, applied mathematics and aeronautics. In 1958, he helped found the University of Science and Technology of China and served as the chair of the department of Chemical Physics.
Since May 1960, Guo served as vice director of Beijing Ninth Research Institute of the Second Ministry of Industry, and became a leader of China's atomic and hydrogen bomb projects. He led work in explosive mechanics, high-pressure physical property equations, aerodynamics, aeronautics, structural mechanics, and weapon experimental environment, and solved a series of important problems.
Guo died of a plane crash on December 5, 1968, when traveling from Qinghai to Beijing.
In December 1982, China's Science Press published The Works of Guo Yonghuai. In 1985, he was awarded a Grand Prize of National Science and Technology Advancement. In 1999, Guo won "Two Bombs, One Satellite Achievement Medal".