• Name: Gardiner, Marguerite (née Power, Countess of Blessington)
• Gender: Female
• Birth Date: 1  September  1789
• Death Date: 4  June  1849
• Occupation: author

Lady Blessington was a socialite who held literary soirées in London which included Thomas Moore, John Galt, and William Jerdan. At one of these events she met Count D'Orsay with whom she was thereafter extremely close. She travelled to Italy in 1822 with her husband and she met Lord Byron in 1832. Subsequently, she published Journal of Conversations with Lord Byron. After her husband died, she returned to writing in the 1830s to supplement her income and published a number of 'silver-fork' novels. Lady Blessington married her step-daughter to D'Orsay, but the couple became estranged, not wholly unrelated to the continuing intimacy of her husband with her step-mother.

Godwin first meets her in 1834, where two early entries are to Blessinton.

• DNB
• Nick Foulkes, Scandalous Society: Passion and Celebrity in the Nineteenth Century (London: Abacus, 2004).

This table lists the people this person is most frequently noted with in the diary.