William FitzWilliam (or William Fitzwilliam) may refer to:
- William Fitzwilliam (Sheriff of London) (1460?–1534), Protégé of Cardinal Wolsey
- William FitzWilliam, 1st Earl of Southampton (c. 1490–1542), English courtier
- William Fitzwilliam (died 1559), MP
- William FitzWilliam (Lord Deputy) (1526–1599), Lord Deputy of Ireland
- William FitzWilliam, 2nd Baron FitzWilliam (1609–1658), English politician
- William Fitzwilliam, 3rd Earl Fitzwilliam (1719–1756), British peer
- William Fitzwilliam, 4th Earl Fitzwilliam (1748–1833), British Whig statesman
- William Wentworth-Fitzwilliam, 6th Earl Fitzwilliam (1815–1902), British peer and Liberal politician
- William Fitzwilliam, Viscount Milton (d. 1835), British Member of Parliament for Malton
Famous quotes containing the word william:
“I shall carry to the Catacombs of Age,
Photographically lined
On the tablet of my mind,”
—Sir William Schwenck Gilbert (1836–1911)