Henry Thomas Mackenzie Bell (March 2, 1856–December 13, 1930), commonly known by his pen name Mackenzie Bell, was an English writer, poet and literary critic. He was a writer for many Victorian era publications, most especially the London Academy, and published several volumes of poetry between 1879 and 1893.

Bell was in Liverpool, England.  He suffered from poor health as a child, a fall resulting from a careless nurse having caused a minor paralytic stroke, and he was educated privately. Though he was trained in preparation for a career in law at Cambridge University, Bell instead chose to study abroad and lived in Portugal, Spain, Italy, France and Madeira. While still a young man, he published his first poetry books The Keeping of the Vow and Other Verses (1879), Verses of Varied Life (1882) and Old Year Leaves (1883).

In 1884, Bell returned to Great Britain and settled in Ealing, London as a professional writer. That same year, he published a well-received biography on Charles Whitehead entitled A Forgotten Genius (1884). He gained a staff position on the London Academy and eventually became its leading literary critic.  Bell went on to become a contributor of articles, poems and letters to various Victorian era publications including The Fortnightly Review, The Pall Mall Magazine, The Atlantic Monthly, The Athenaeum, The Speaker, The Literary World, Temple Bar, The Lady's Realm, Black and White and The Academy. He also wrote articles for the Dictionary of National Biography, The Poets and the Poetry of the Century and the Savage Club Papers.

During the 1890s, he published a second series of poetry collections Spring's Immortality and Other Poems (1893), Pictures of Travel and Other Poems (1898) and Collected Poems (1901). Four years after the death of Rossetti, he published her biography Christina Rossetti: A Biographical and Critical Study (1898).

Bell was also active politically during this time as a Liberal Imperialist. He was a charter member of W.E. Forster's Imperial Federation Committee, lectured for the Social and Political Education League and on four occasions contested St George Hanover Square (or the London County Council) on behalf of the Liberal Party. For several years, he was also a member of the Athenaeum.