Louisa, Marchesa Malacrida de Saint-August (née Louisa Nadia Green, 15 June 1895 – 3 October 1934), known by the pen names Nadja Malacrida and Nadja, was an English writer, radio broadcaster, racing driver, and socialite. A novelist, playwright, and poet, she published three books of war poetry during the First World War. An Italian aristocrat by marriage, she was a prominent figure of 20th-century London high society.