Isabella Mercia McDonagh (3 January 1899 – 5 March 1982), also known as Marie Lorraine, was an Australian actress who often worked in collaboration with her sisters Paulette and Phyllis.
Isabella, alongside her two sisters made history by owning and running a film production company, therefore becoming the first Australian women to do so.She visited Hollywood in 1934 but did not elect to stay on and make a career there.