William Hewlett may refer to:
William Hewlet (1630s–1660), convicted of executing Charles I of England in 1649 but reprieved Bill Hewlett (1913–2001), American engineer and co-founder of the Hewlett-Packard Company Will Hewlett (1876–1921), Welsh trade unionist and socialist activist W. H. Hewlett (1873–1940), Canadian composer, organist, and choir conductor
See also William Hewett William Hewitt (disambiguation)