Ernest Julius Walter Simon, CBE, FBA (10 June 1893 – 22 February 1981) was a German sinologist and librarian.
He settled in London where he spent the rest of his life apart from brief periods in other countries as a visiting professor.
He taught Chinese at the School of Oriental and African Studies, University of London from 1947 to 1960.
He made important contributions to historical Chinese phonology and Sino-Tibetan linguistics.
His Chinese name was Ximen Huade (西門華德, Xīmén Huádé).