Alexander Donchenko (born 25 March 1998) is a German chess Grandmaster and is considered to be one of the strongest German chess players. He won the German Chess Championship in 2019 and represented Germany in the 43rd Chess Olympiad.

Donchenko was introduced to chess at the age of five and won the U8 German Championship in his early years playing the game. Donchenko went on to solidify his early success with several accolades in youth chess, including victories in the Youth Bundesleague in 2015 and German U25 Championship in 2016. Officially granted the prestigious International Master title in 2014, he was later awarded the title of Grandmaster in 2015 by FIDE, the international chess federation.

In the adult circuit, Donchenko produced many commendable performances. Notable among these were his first place finishes at the 2019 German Chess Championship and the 22nd Neckar Open. He also won the Karpov Trophy tournament in 2021, outpacing notable players such as Alexei Shirov and Maxime Vachier-Lagrave.