Jessie Smither, Duchess of Leinster (25 August 1885 – 20 October 1960), known by her stage name Denise Orme, was an English music hall singer, actress and musician who appeared regularly at the Alhambra and Gaiety Theatres in London in the early years of the 20th century. Married, successively, to an English baron, a Danish millionaire, and an Irish duke, she was the maternal grandmother of Aga Khan IV.