Amelia Osborne, Marchioness of Carmarthen

The Marchioness of Carmarthen
Amelia Osborne, painted by François-Hubert Drouais
Born	Lady Amelia Darcy 12 October 1754
Died	27 January 1784(1784-01-27) (aged 29)
Spouse(s)	Francis Osborne, Marquess of Carmarthen ​ ​ (m. 1773; div. 1779)​ John "Mad Jack" Byron (m. 1779–84; her death)
Children	George Osborne, 6th Duke of Leeds Mary Pelham, Countess of Chichester Francis Osborne, 1st Baron Godolphin Augusta Leigh
Parent(s)	Robert Darcy, 4th Earl of Holderness Mary Doublet

Amelia Osborne (née Darcy), Marchioness of Carmarthen and de jure 12th Baroness Darcy de Knayth and 9th Baroness Conyers and 5th Countess of Mértola (12 October 1754 – 27 January 1784) was a British peer and a Portuguese countess.

Amelia was the only child of the Robert Darcy, 4th Earl of Holderness and his wife, Mary Doublet. On 29 November 1773, she married Francis Osborne, Marquess of Carmarthen and they had three children:

• Lord George William Frederick Osborne (21 July 1775 – 10 July 1838), later 6th Duke of Leeds; married Lady Charlotte Townshend, daughter of the 1st Marquess Townshend, on 17 August 1797 and had issue.
• Lady Mary Henrietta Juliana Osborne (1776–1862); married Thomas Pelham, 2nd Earl of Chichester (28 April 1756 – 4 July 1826) in 1801 and had issue.
• Lord Francis Osborne (18 October 1777 – 15 February 1850), later 1st Baron Godolphin; married The Hon. Elizabeth Eden, third daughter of the 1st Baron Auckland, on 31 March 1800 and had issue.

Lord and Lady Carmarthen divorced in May 1779 and a month later, Amelia then married John "Mad Jack" Byron (father of the poet, Lord Byron) and they had one daughter, Augusta Leigh. A year earlier, Amelia had inherited the right to her father's baronies of Darcy de Knayth and Conyers (although this wasn't confirmed until 1798, long after her death) and also inherited the Portuguese countship of Mértola from him. On her own death in 1784, they were inherited by her eldest son, George.