Winifred Cochrane, Countess of Dundonald (Welsh: Winifred, Iarlles Dundonald) was born on 16 April 1859. She was a philanthropist, a Lady of Grace of the Order of St John, Marchioness of Maranham, and was known within Wales by her bardic name, Rhiannon. She was the Welsh wife of Douglas Mackinnon Baillie Hamilton Cochrane (1852–1935).