Marina Fideli  (Mezzosopran) was born in Volos, Greece. After having obtained her Diploma in Economic Sciences at the National and Kapodistrian University of Athens, she started her vocal studies at the Modern Conservatory of Athens by Giorgos Zervanos and graduated by being awarded a distinction and the first prize. She attended master classes under well recognised artists such as Kostas Paskalis, Ileana Cotrubas and Ks. Margarita Lilowa and obtained singing lessons with Frangiskos Voutsinos, Aris Christofellis and Prof. Daphne Evangelatos. Furthermore, she continued her studies at the Hochschule für Musik und Darstellende Kunst in Wien under the direction of Ks. Prof. Margarita Lilowa (vocal studies) and Prof. Curt Malm (dramatic interpretation), graduating in 1997.

Since 1997, she has been an integral guest at the Greek National Opera in Athens, where she sang roles such as Cherubino (Le nozze di Figaro), Dorabella (Così fan tutte), Smeton (Anna Bolena), Nicklaus (Les contes d' Hoffmann), Adalgisa (Norma), Cenerentola (La Cenerentola) and important roles in Baroque operas such as Alcina (Orlando Furioso) und Aristea (Olympiade). In addition in 2010, she has been invited by the Greek National Opera where she had a successful appearance as Carmen and more recently as Marouso, in the First World premiere Opera of G. Koumendakis "The murderess".

She also appeared on as a soloist in the Megaron Mousikis Athens, the Megaron Mousikis Thessalonikis, the Athens and Delfi Festival and the Kammeroper Athens with all major Greek Symphonic Orchestras as well as, with well-known Orchestras, such as the Berliner Sinfonie Orchester, the Hamburger Symphoniker, the Budapest Opera Orchestra and the Solisti Veneti. In 2007, during the celebration of the Cultural Year of Greece in China, host of the 2008 Olympic Games, she has participated in a concert in Beijing representing her homeland accompanied by the State Orchestra of Thessaloniki.

She has been working alongside with prominent conductors such as Yoav Talmi, Wolfgang Rögner, Armando Gatto, Claudio Scimone, Konstantinos Karidis, Michael Schoenwandt, Lukas Karytinos, Gianpaolo Sanzogno, Georg Fritzsch, Andreas Spering, Reinhard Goebel and Ruben Dubrovsky and directors such as Pier Luizi Pizzi, Götz Friedrich, Spyros Evangelatos, Georg Köhl, Uwe Schwarz, Daniel Karasek, Thomas Enzinger, Thomas Wünsch, Arila Siegert, Matthias von Stegmann, Ks. Brigitte Fassbaender and Ansgar Weigner.
 
Since 2003, Marina Fideli has been a permanent member of the Opera House in Kiel. Her vocal expressiveness, her stage presence and her wide-ranging repertoire of the mezzo-soprano Fach are just some of the qualities, that have been standing out consistently all these years in roles such as Adalgisa (Norma), Giovanna Seymour (Anna Bolena), Preziosilla (La Forza del destino), Laura (La Gioconda),  Charlotte (Werther), Sesto (La clemenza di Tito), Orlofsky (Fledermaus), Carmen (Carmen), Eboli (Don Carlos), Isabella (L' Italiana in Algeri), Amneris (Aida), Ježibaba (Rusalka), Ortrud (Lohengrin), Giulietta (Les contes d' Hoffmann), Azucena (Trovatore), Küsterin (Jenufa), Suzuki (Madama Butterfly),  Brangäne (Tristan und Isolde), Larina (Eugene Onegin) and L. Begbick (The Rise and Fall of the City of Mahagonny).

In the season 2013/2014, she was cheered by the Kiel audience particularly for her strong performance and her great vocal interpretation as Küsterin Buryja in the successful Kiel production of the opera Jenufa, which was crowned with the rare Opernfreund-Stern.

Her repertoire also features symphonic works, oratorios and lieder. Here upon, it is worth mentioning the Verdi Requiem, the Wesendonck-Lieder of R. Wagner and Das Lied von der Erde of G. Mahler.