Charlotte, Lady Williams-Wynn (née Grenville; c. 1754 – 29 September 1830), was a British aristocrat.

Lady Williams-Wynn was a first cousin of Prime Minister William Pitt through her paternal aunt Hester Grenville, who married William Pitt, 1st Earl of Chatham.

Her mother and father died in 1769 and 1770 respectively, and guardianship of their daughter Charlotte was assumed by George's elder brother, Richard Grenville-Temple, 2nd Earl Temple.

The couple had eight children, six of whom survived to adulthood, including: Sir Watkin died on 24 July 1789.

Upon her husband's death, Lady Williams-Wynn became the sole administrator of his Welsh estates under the terms of his will, and functioned as such until her eldest son reached the age of majority.