Williams-Wynn is a surname. It may may refer to:
- Charles Watkin Williams-Wynn (elder) (1775–1850), Secretary at War
- Charles Watkin Williams-Wynn (younger) (1822–1896), his son
- Sir Watkin Williams-Wynn, 3rd Baronet (1692–1749)
- Sir Watkin Williams-Wynn, 4th Baronet (1749–1789)
- Sir Watkin Williams-Wynn, 5th Baronet (1772–1840)
- Sir Watkin Williams-Wynn, 6th Baronet (1820–1885)
- Sir Herbert Lloyd Watkin Williams-Wynn, 7th Baronet (1860–1944)
- Sir Watkin Williams-Wynn, 8th Baronet (1891–1949)
- Sir (Owen) Watkin Williams-Wynn, 10th Baronet (1904–1988)
- Sir (David) Watkin Williams-Wynn, 11th Baronet (born 1940)
- Sir Henry Watkin Williams-Wynn (1783–1856), diplomat.