|Full name||Zahar Efimenko|
|Born|| 3 July 1985
|Peak rating||2708 (March 2011)|
Zahar Efimenko (ukr. Захар Єфименко; born 3 July 1985) is a Ukrainian chess player. He has been a grandmaster since 2002.
In 1999 Efimenko won the U-14 World Youth Chess Championship in Oropesa del Mar, Spain. In the same year he was a member of the Ukrainian national youth team, which won the U-16 Chess Olympiad in Artek, Ukraine. Efimenko has won several chess tournaments since then, among them the 2001 Stork Young Masters in Hengelo, Netherlands. In 2005 he tied for 1st-5th with Levon Aronian, Kiril Georgiev, Alexei Shirov and Emil Sutovsky in the Gibraltar Chess Festival. He became champion of Ukraine in 2006. In 2007, he tied for 1st-6th with Vitali Golod, Mateusz Bartel, Yuri Yakovich, Michael Roiz and Mikhail Kobalia in the 16th Monarch Assurance Isle of Man International tournament. In May 2010, he tied for 1st-2nd with Victor Bologan in the 40th Bosna International tournament in Sarajevo.
Efimenko was a member of the victorious Ukrainian team that won the gold medal at the 2010 Chess Olympiad in Khanty-Mansiysk. In the direct encounter against main rival Russia, he defeated Vladimir Malakhov.