John Zylinski, also known as Jan or Janek Zylinski was a Polish property developer living in United Kingdom who claimed to be a prince from a line of Polish aristocracy but grew up in the émigré community in London after the Second World War. His early career was in art journalism and he established an art business. He then became a property developer, specialising in fixer-uppers, and made a fortune. He was known for his public activism and support for Polish causes in the United Kingdom, recreating a Polish palace in Ealing, and founding the charity Polish Heroes and a political party, Duma Polska – Polish Pride.