Plimsoll may refer to:
Plimsoll (surname) A symbol (⦵ or o) that is used as a superscript in the notation of thermodynamics to indicate a specific arbitrarily chosen non-zero reference point (standard state). Plimsoll line or Plimsoll mark on a ship's hull, named after Samuel Plimsoll Plimsoll shoe, which is named for the shoe's horizontal lines, which resemble the Plimsoll line
See also The Plimsouls, an American rock band.