Infobox last updated on: November 10, 2008.

Eleni Daniilidou (Greek: Ελένη Δανιηλίδου; born September 19, 1982) is a Greek tennis player born in Chania, on the island of Crete.

As of 2006, she has won five WTA singles titles and one doubles title. In 2003, she reached the Australian Open mixed doubles final. Her highest singles ranking has been 14th. 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.