Born as the eldest daughter in the village of Eyam, Derbyshire, to Thomas Seward who was a rector there, and was to become the Canon of Lichfield. Anna, known as the "Swan of Lichfield", never married and looked after her father until his old age.

Anna had a series of intense involvements with women, beginning with her foster sister Honora Seyd who entered the Seward household when Anna was 13, and became Anna's closest companion after the death of her sister Sarah in 1763.

Anna was deeply affected by Honora's marriage to Richard Lovell Edgeworth in 1773, and went into mourning for the loss of her friend. Anna attended Lady Anne Miller's literary circle in Batheaston, beginning to write in her mid-thities. She had close friendships with Penelope Weston and Elizabeth Cornwallis, and was a correspondent of the Ladies of Llangollen.

She furnished Boswell with many details of Dr Johnson's early life. In 1802 she wrote an admiring letter to Sir W. Scott, who found some merit in her poetry and edited her works in 3 volumes with a memoir, in 1810, at her suggestion. Her letters were published in 1811. After almost two hundred years of neglect, her poetry is now more favourably acknowledged and is beginning to reappear in Romantic anthologies. A monument to Anna Seward, the Swan of Lichfield, can be found in the Cathedral.