Eleni Daniilidou, Greek tennis player
Eleni Daniilidou (Greek: Ελένη Δανιηλίδου; [eleˈni ðaniˈiliðu]; born 19 September 1982) is a Greek former tennis player from the island of Crete.

She is considered one of the best Greek tennis players of the Open Era, winning five singles titles and three doubles titles on the WTA Tour. In 2003, she reached the mixed-doubles final of the Australian Open, making her the first Greek player to have reached a Grand Slam final. Her highest singles ranking is world No. 14, making her the only female tennis player from Greece to have reached the top 20 until Maria Sakkari in February 2020. No male tennis player had achieved this until Stefanos Tsitsipas reached 15th place in August 2018. By beating Justine Henin in the first round of the 2005 Wimbledon Championships, she became the first player to defeat a reigning French Open champion in the first round of Wimbledon.