Dame Una Constance Pope-Hennessy, DBE (née Birch; 21 April 1875 – 16 August 1949) was a British writer, historian, and biographer.

She was the daughter of Sir Arthur Birch, and married Major (later Major-General) Richard Pope-Hennessy in 1910.

For this work, she was appointed Dame Commander of the Order of the British Empire (DBE) in the 1920 civilian war honours.

In 1929 she published Three English Women in America, charting American experience of Frances Trollope, Fanny Kemble and Harriet Martineau.

Her final two books were translations, A Czarina's Story and Canon Charles Kingsley both published in 1948 a year before her death.