David S. C. Chu (朱思九; pinyin: Zhū Sījiǔ; born May 28, 1944) is a retired American civil servant and consultant. He was born in New York, New York on May 28, 1944. He served as the President and CEO of the non-profit Institute for Defense Analyses from 2009 to 2019. From 2001 to 2008, he served as Under Secretary of Defense for Personnel and Readiness in the George W. Bush administration. He is a fellow of the National Academy of Public Administration and a recipient of its National Public Senior Award. He holds the Department of Defense Medal for Distinguished Public Service with silver palm.