De Witt is a surname of Dutch origin meaning "the white". Notable people with the surname include:
De Witt (family), a patrician family from the Dutch Golden Age
Johan de Witt (1625–1672), Grand Pensionary of Holland
Cornelis de Witt (1623–1672), Dutch politician
Andries de Witt (1573–1637), Grand Pensionary of Holland
Jacob de Witt (1589–1674), burgomaster of Dordrecht
Jacob De Witt (1785–1859), Canadian politician
Alexander De Witt (1798–1879), American politician
Bryce De Witt (1923–2004), Theoretical physicist
Cécile DeWitt-Morette (1922-), Theoretical physicist
David M. De Witt (1837–1912), American politician
Francis B. De Witt (1849–1929), American politician
Jacob H. De Witt (1784–1867), American politician
Simeon De Witt (1756–1834), American cartographer
