Mary Elizabeth Townshend

Mary Elizabeth Pitt, Countess of Chatham (born Mary Elizabeth Townshend; 2 September 1762 – 21 May 1821), was an English noblewoman and political campaigner. She was the daughter of Thomas Townshend, 1st Viscount Sydney, and Elizabeth Powys. Her siblings included Frances Townshend (1772–1854), who married George Rice, 3rd Baron Dynevor, and Harriet Townshend (1773–1814), who married Charles Montagu-Scott, 4th Duke of Buccleuch.

On 9 July 1783, she married John Pitt, 2nd Earl of Chatham, at St George's, Hanover Square. Her husband was a member of the Pitt family; her brother-in-law, William Pitt the Younger, served as prime minister later that same year, and her father, Thomas Townshend, became Home Secretary in 1784. In 1799, her husband was appointed First Lord of the Admiralty.

In 1800, her eldest brother John inherited the viscountcy upon their father's death, having been an MP since 1786.

Throughout her life, Mary Elizabeth Pitt experienced various health issues. She suffered from rheumatism shortly after her marriage, which confined her to bed and later necessitated the use of a wheelchair. Her health challenges were compounded by bouts of mental illness following her brother-in-law's death in 1806. In October 1807, she attempted suicide, which led to her being less publicly active over subsequent years. Her marriage was childless, and the earldom became extinct upon her husband's death in 1835.

Mary Elizabeth Pitt died, possibly due to liver failure, at her residence in Hill Street, Mayfair, London. She was interred in the Pitt family vault at Westminster Abbey.