William Napier may refer to:
William Ewart Napier (1881–1952), American chess master William Francis Patrick Napier (1785–1860), British soldier and military historian William Napier (astronomer) (born 1940), astronomer and author William Napier, 9th Lord Napier (1786–1834), Royal Navy officer, politician and diplomat William Napier (novelist), historical novelist pseudonym of Christopher Hart William Napier (VC) (1828–1908), English recipient of the Victoria Cross William Napier (Royal Navy officer) (1877–1951), British admiral William Craig Emilius Napier (1818–1903), British general William Napier (lawyer) (1804–1879), Singapore lawyer and newspaper editor; Lieutenant-Governor of Labuan William Joseph Napier (1857–1925), member of parliament for Auckland, New Zealand William Napier, 11th Lord Napier (1846–1913), British peer William Napier, 13th Lord Napier (1900–1954), Scottish soldier and courtier William Napier, 7th Lord Napier (1730–1775), Scottish peer Sir William Napier, 3rd Baronet (1867–1915), British baronet and soldier See also William Napper (disambiguation)