Alessandro Guagnini or Aleksander Gwagnin (1538 in Verona – 1614 in Kraków) was a Polish writer, soldier, chronicler and historian of Italian heritage. He spend almost his entire life in Poland, became a naturalized Pole and adopted the Polish version of his name "Gwagnin". He also served in the Polish military in Vitebsk at the time part of the Vitebsk Voivodeship in the Polish–Lithuanian Commonwealth.
Gwagnin is known for publishing the Latin book Sarmatiae Europeae descriptio, quae Regnum Poloniae, Lituaniam, Samogitiam, Russiam, Masoviam, Prussiam, Pomeraniam... complectitur, usually translated as "A Description of Sarmatian Europe" (printed in Kraków, 1578), which contained descriptions of the countries of Eastern Europe (history, geography, religion, traditions, etc.).
Maciej Stryjkowski, who was his subordinate, alleged that Guagnini stole a manuscript of the Chronicle of Poland, Lithuania, Samogitia and all of Ruthenia from him and was not the author of the book. Stryjkowski protested before the Polish king and his claims were recognized in 1580, but the book continued to be printed under Guagnini's name and was even translated into Polish. An expanded edition appeared in 1611.
The chronicle included portraits of Lithuanian dukes for the first time. Despite the images being purely fictional and having nothing to do with actual dukes, anachronistic clothes and weapons, and that some of the images illustrated multiple people, the portraits highly influenced future depictions of the Grand Dukes of Lithuania. To this day they remain the most popular portraits used in many history books.
- Zdenek, David (2003). Finding the Middle Way: The Utraquists' Liberal Challenge to Rome and Luther. Woodrow Wilson Center Press. p. 432. ISBN 0801873827.
- Annotated footnote to an edition of Compendium Maleficarum by Francesco Maria Guazzo and Montague Summers, 
- Poe, Marshall (2003). Early Exploration of Russia: The Moscovia of Antonio Possevino, S.J. Taylor & Francis. p. 153. ISBN 041532274X.
- Oleg Łatyszonek, "From White Russia to Belarus" Annus Albaruthenicus, no. 5, 2004
- For example, Gimtoji istorija. Nuo 7 iki 12 klasės
- Francysk Skaryna Museum in London
- Julia Radziszewska, Maciej Stryjkowski, historyk-poet z epoki Odrodzenia, Katowice, 1978.
- Gwagnin: scan of the original book (Latin)
- Guagnini: The Description of Muscovy, part 1 (Russian)
- Guagnini: The Description of Muscovy, part 2 (Russian)