Lady Mary Agatha Russell (1853 – 23 April 1933) was the daughter of the 1st Earl Russell and Frances, Countess Russell, and the aunt of Bertrand Russell. She was the co-editor of her mother's posthumously published memoirs, Lady John Russell: A Memoir with Selections from Her Diaries and Correspondence.
In 1912, Russell published a compilation of quotations and selections from authors, philosophers, poets, etc. entitled Golden Grain: Thoughts of Many Minds. The entries in Golden Grain are organized by date through a single year. It was prefaced by Frederic Harrison and published by James Nisbet and Company of London in 1912.