Alexandros Nikolaidis (born October 17, 1979 in Thessaloniki) is a Greek taekwondo athlete. Initially the home favorite, he eventually won the silver medal at the 2004 Olympics held in Athens after losing to Moon Dae-Sung of South Korea in the gold medal match.
On March 24, 2008 Alexandros Nikolaidis had the honour to be the first torch-bearer of the 2008 Summer Olympics torch relay.
Later in the same year on April 11, he won the European Championship in Rome.
At the 2008 Beijing Olympics, Nikolaidis won another Olympic silver medal in the +80 kg category, after losing to Cha Dong-Min of South Korea in the final.
In July 2011, he managed to secure a place at the 2012 Olympic Games by placing third in the 2011 World Taekwondo Olympic Qualification Tournament in Baku, Azerbaijan by defeating Liu Xiaobo of China in the 3rd place play-off. He carried the flag for Greece during the Parade of Nations at the 2012 Summer Olympics in London.
On August 11, 2012 Nikolaidis began and ended his Olympics participation in a "preliminary round" bout against Bahri Tanrikulu. Nikolaidis lost 7-3 overall.
He retired in 2014. He now coaches the junior Olympic team for Greece.