Kacper Piorun (born 24 November 1991) is a Polish chess player who received the FIDE title of Grandmaster (GM) in September 2012.

[12] He won team gold with Poland at the World Chess Solving Championship in Jesi 2011,[9] Kobe 2012,[13] Batumi 2013,[14] Bern 2014,[10] Ostróda 2015,[11] Belgrade 2016 and Dresden 2017 events.

During the 2018 Chess Olympiad in Batumi, he defeated the thirteenth best player in the world, Hikaru Nakamura,[15] and claimed fourth place overall with the Polish team.

At the 2022 Chess Olympiad he was part of the Polish team, that came at place 9 in the final results.

He tied for 3rd to 11th place in the 2019 European Individual Championship with David Anton Guijarro, Ferenc Berkes, Niclas Huschenbeth, Sergei Movsesian, Liviu-Dieter Nisipeanu, Grigoriy Oparin, Maxim Rodshtein, and Eltaj Safarli.