RMS Strathaird, later TSS Strathaird, was an ocean liner of the Peninsular and Oriental Steam Navigation Company (P&O). She was the second 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 Strathaird 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". Strathaird and her sister ship RMS Strathnaver were Royal Mail Ships that worked P&O's regular liner route between Tilbury in Essex, England and Brisbane in Queensland, Australia. In 1935 they were joined by the third ship of the class, RMS Strathmore.