Janusz Leon Wiśniewski is a Polish scientist and writer, born on August 18, 1954, in Toruń, Poland. He gained recognition primarily for his novel S@motność w Sieci, translated into English as Loneliness on the Net. The novel, published in 2001, has been translated into numerous languages and inspired a popular Polish film.

Wiśniewski holds a Master of Physics and a Master of Economics from Nicolaus Copernicus University in Toruń. He earned a PhD in Information Technology from Warsaw University of Technology and completed a Habilitation in Chemistry at the Technical University of Łódź. He is notably one of the authors of the computer program AutoNom, which is a naming tool for organic substances in the IUPAC nomenclature.

Currently, Wiśniewski resides and works in Frankfurt, Germany. In addition to his native Polish, he is fluent in German, English, and Russian.