Sergei Tkachenko (born in 1963, near Odessa, Ukraine) is a member of the Ukrainian team that won the 5th World Chess Composition Tournament in 1997 and which came second in 2000, 2004, 2013, and 2017. He has won the studies section of the Ukrainian Chess Composition Championship six times and has won prizes, many of them for first place, in over 100 international chess composition tournaments. Sergei coaches the Ukrainian chess composition team. He is also the press secretary of the Chess Composition Committee of the Ukrainian Chess Federation. Sergei is an award-winning author who has written 18 chess books (in Russian), including compositions and on historical themes. He is deputy chief editor of a Ukrainian chess composition magazine called Problemist of Ukraine and has a regular studies column on the ChessPro website. Sergei is a member of the Ukrainian Union of Journalists. He is a historian and archivist, as well as being a mechanical engineering graduate.