RMS Strathnaver, later SS Strathnaver, was an ocean liner of the Peninsular and Oriental Steam Navigation Company (P&O). She was the first of five sister ships in what came to be called the "Strath" class. All previous P&O steamships had black-painted hulls and funnels but Strathnaver and her sisters were painted with white hulls and buff funnels, which earnt them the nickname "The Beautiful White Sisters" or just "The White Sisters". Strathnaver and her sister ships RMS Strathaird and RMS Strathmore were Royal Mail Ships that worked P&O's regular liner route between Tilbury in Essex, England and Brisbane in Queensland, Australia.