Plimsoll is a surname, and may refer to: James Plimsoll, a governor of Tasmania John Plimsoll, South African cricketer Oliver Plimsolls, fictional character in The League of Gentlemen (comedy) Samuel Plimsoll, British politician Plimsoll may also refer to: the plimsoll symbol o that's used as a superscript in the notation of thermodynamics to indicate an arbitrarily chosen non-zero reference point ("standard state"). Plimsoll line or Plimsoll mark on a ship's hull, named after Samuel Plim… (More on Plimsoll)