Shih-Ying Lee or S. Y. Lee (Chinese: 李詩穎; pinyin: Lǐ Shīyǐng; April 30, 1918 – July 2, 2018) was an American aerodynamicist, businessman, inventor, and mechanical engineer who was noted for his research and innovation in hydrodynamics-related technologies. He was also a Professor Emeritus at the Massachusetts Institute of Technology.