Eliza Courtney, French daughter of Georgiana, Duchess of Devonshire (d. 1859)
Elizabeth Courtney (20 February 1792 – 2 May 1859) was the illegitimate daughter of the Whig politician and future Prime Minister Charles Grey, 2nd Earl Grey, and socialite Georgiana, Duchess of Devonshire, while Georgiana was married to William Cavendish, 5th Duke of Devonshire.

The Duchess was forced by her husband to relinquish Eliza shortly after her birth, to be raised by Charles Grey's parents, Charles Grey, 1st Earl Grey, and Elizabeth Grey, Countess Grey. The Duchess came to visit Eliza in secret. Eliza named her firstborn daughter Georgiana.

The name Courtney, extinct since the death of Charles Kelland Courtney in 1761, was derived from her great-uncle, her maternal grandmother's brother, William Poyntz (d. 1809), having married Isabella (d. 1805), sister and co-heiress of the aforementioned Charles Courtney, the last of the west country family of Courtney of Trethurfe and Courtney of Tremeer.