Isabella Fenwick (1783 – 1856) was a 19th-century British amanuensis (secretary), and a confidante, advisor, and friend of William Wordsworth and his family in his later years.

"[7] Fenwick's companionship may have helped fill the void left by his sister Dorothy Wordsworth, who was by this point incapacitated by mental illness.

Mary Wordsworth "attached herself to Miss Fenwick with a warmth and energy of nature which took no account of years," wrote Henry Taylor.

[12] While editing The Prelude and preparing it for posthumous publication, Wordsworth spent a lot of time thinking about his poetic reception after his death.

[13] At the urging of Fenwick and his daughter Dora, Wordsworth decided to set down the biographical details surrounding the composition of many of his poems.