Williams is an elected member of National Academy of Engineering (1988) and also in American Academy of Arts and Sciences (2010). He is a fellow of The Combustion Institute. He is elected as a fellow of APS in 2002. He is also a member of AIAA, SIAM etc. He holds an honorary doctorate degree from Technical University of Madrid. He has been in the editorial board of various journals, currently he is in the editorial board of Progress in Energy and Combustion Science, Combustion Science and Technology. He was a member of the National Construction Safety Team Advisory Committee in reporting the Collapse of the World Trade Center. Some of his awards include: