Nikolay Vladimirovich Davydenko (Russian: Николай Владимирович Давыденко; born June 2, 1981 in Severodonetsk, Ukrainian SSR, Soviet Union) is a Russian tennis player. Davydenko's best result in a Grand Slam tournament has been reaching the semi-finals, which he has done on four occasions – twice each at the French Open and the U.S. Open. He was runner-up at the 2008 Tennis Masters Cup and then went one better the next year winning the 2009 ATP World Tour Finals. He has also won three Masters Series shields. He is one of the players who has a winning record against Rafael Nadal.
Years later, Davydenko explained his peripatetic youth, "I stayed four years in Russia. Eduard worked as a tennis coach for kids and we practised together. He pushed me pretty hard. At 15 we left for Germany. A Russian who lived there convinced Eduard it would be better for me and help me to learn more about my game with better coaches. In Europe I could play more tournaments and earn more money than in Russia."
Davydenko was granted Russian citizenship in 1999 at the age of 18, and has represented Russia ever since. In 2007 he applied for Austrian citizenship (so as to obtain a dual citizenship), and has also previously applied for German citizenship.