Born in Limassol, Cyprus, Theokleous was raised in the island's capital, Nicosia. While still at school, she studied music at the National Conservatory of Cyprus. When she finished school, she went to Le Studio des Variétés in Paris, where she studied music, theatre, and dancing. Afterwards she went to the Berklee College of MusicinBoston, where she supplemented her musical studies with courses of harmony and instrumentation.
In 1989, she moved to Athens to work with several artists, sing in compilations, and in 1991, she released her first personal album Gia Proti Fora.
Their first collaboration was in 1992 with the album Kane pos m agapas. The album did very well in sales and received very high airplay. In 1993, Evridiki released her album Missise Me (Hate Me), making her one of the most successful singers in Greece. Missise Me is supposed to be Evridiki's favourite album among her fans.
In 1994, while wanting to try out something new, she started working on her next album Fthinoporo Gynaikas (Woman's Autumn). Inspired by the idea of her growing older as the time passes, the album was a mixture of pop and Greek folklore music. The same year (1994) she married Giorgos Theofanous. The composer has always considered Evridiki as his muse, even after they got divorced in 2000. Together, they had a son Angelos, who was born in November 1996.
Theofanous was the main composer and producer of Evridiki's first nine albums while he collaborated with Minos EMI A&r manager Vangelis Yannopoulos in 1998 and 1999. Albums like Dese Mou ta Matia (1998) (her first Golden album), To Koumpi (1999) and Ola Dika Sou (2000), with their pop/laiko sound, are characteristic of Evridiki's Theofanous period.
In 2002, Evridiki made a turn in her career. After her divorce she cooperated no more with her ex-husband and turned from pop music to rock/alternative. In her 2002 album Live Ki Allios she performed well known rock songs revealing another side of hers. In 2002, she also performed on stage as "Taptim" in the musical The King and I, produced by Mimi Denisi with very positive acceptance by public and critics.
After having a studio music break for almost three years, Evridiki released the album Oso Fevgo Gyrizo (2003), in which she wrote two songs. This record would be a turning point in Evridiki's career by characterising a new era for her. Since then she has been recognised as the most successful Greek female rock singer [citation needed]. She released another critically acclaimed record Sto Idio Vagoni (2005). In both albums she collaborated to musician Dimitris Korgialas
In 2009, Evridiki released the album Etsi Ine I Agapi, performing together with Dimitris Korgialas. The next year (2010) the CD-single Etsi Apla was released.
In 2017, Evridiki collaborated with Lopodites, a local pop-rock band based in Cyprus. The collaboration continued in 2018 when she appeared on stage once again with Lopodites and female singer Georgia Kerala (vocalist of the band Ble) at Ravens Music Hall in Limassol.
She represented Cyprus in the Eurovision Song Contest in 1992 (Malmö, Sweden) with the song "Teriazoume" (finishing in eleventh place), and then in 1994 (Dublin, Ireland) with Ime Anthropos Ki Ego. The latter caused controversial reactions from critics and the audience due to the song's political allusion to The Cyprus Problem. On the other hand, it became a hot favourite to win because of its ethnic sound and her very sentimental performance. As with her first entry in the contest two years previously, Evridiki took eleventh place. Evridiki also appeared as a backing vocalist in Eurovision on three separate occasions, in 1983, 1986, and 1987.
In 2007, she was selected to represent Cyprus for a third time, in that year's contest, with a French-language song Comme Ci, Comme Ça whose lyrics were written by Posidonas Giannopoulos and its music composed by Dimitris Korgialas. Despite being one of the favourites to win the competition, it failed to make it through the semi-final stage of the competition finishing 15th.
