MS Saga Ruby is a cruise ship that was owned and operated by Saga Cruises. She was built as the combined ocean liner/cruise ship Vistafjord in 1973 by Swan Hunter Shipbuilders in the United Kingdom for the Norwegian America Line. In 1983 she was sold to Cunard Line, retaining her original name until 1999 when she was renamed Caronia. In 2004 she was sold to Saga and sailed as Saga Ruby until sold in 2014 for use as a floating hotel and renamed Oasia.