Greek mezzo-soprano Mary-Ellen Nesi has received the highest critical acclaim for her performances in opera, concert and recital.

She has appeared in many major operatic roles such as the title roles in Handel’s  Serse, Oreste, Rodrigo and Faramondo, Ruggiero in Alcina, Andronico in Tamerlano, Megacle in the first world revival of Paisiello’s L’Olimpiade, Orfeo in Orfeo ed Euridice, Adalgisa in Norma, Rosina in Il Barbiere di Siviglia, Giovanna Seymour in Anna Bolena, Ottavia in L'Incoronazione di Poppea, Penelope in Il Ritorno d’Ulisse in Patria, Antiope in the first world revival of Vivaldi’s Ercole su’l Termodonte (in Spoleto Festival 2006 under Alan Curtis), Anastasio in Vivaldi’s Giustino, Mitrena in Vivaldi’s Motezuma, Octavian in Der Rosenkavalier, Dorabella in Cosi Fan Tutte, Cherubino in Le Nozze di Figaro, Ramiro in La Finta Giardiniera, Hansel in Hansel und Gretel, Bradamante in Orlando Furioso, Teresa in La Sonnambula, Lola in Cavalleria Rusticana, Maddalena in Rigoletto,Tebaldo in Don Carlos and principal roles in operas by contemporary Greek composers such as Helen of Sparta, in The Return of Helen  by Thanos Mikroutsikos, Night in Manuel Salinas by Periklis Koukos and others.

Mary-Ellen Nesi has appeared at major international venues such as the Carnegie Hall, the Avery Fisher Hall (NY), the Places des Arts (Montreal), the Bayerische Staatsoper (Munich), the Théâtre de Champs-Elysées (Paris), the Concertgebouw (Amsterdam), the Teater an der Wien (Vienna), the Arriaga (Bilbao), the Sao Carlos Opera (Lisbon), the Comunale of Florence, Ferrara and Modena, the Municipale of Piacenza, the Baden-Baden Festspielhaus, the Frauenkirche (Dresden), the Tonhalle (Duesseldorf), the Monumental  (Madrid), the Caio Melisso (Spoleto), the Wiesbaden Opera House,  the Teatro de la Maestranza (Seville), the Teatro Olimpico (Rome) and festivals such as the Spoleto Festival, the Göttingen and the Halle Händel Festspielen, the Semana de la Musica Religiosa di Cuenca, the Santiago de Compostela Festival, the Athens Festival and she is a regular guest at the Greek National Opera, the Megaron of Athens, the Megaron of Thessaloniki, the Opera of Thessaloniki.

As a soloist, she has performed with the Montreal Symphony Orchestra under Charles Dutoit, the RTV Orchestra of Spain under M.Gomez-Martinez, the Complesso Barocco under Alan Curtis, the Bayerische Staatsorchester under Ivor Bolton, the Venice Baroque Orchestra under Andrea Marcon, the Washington Bach Consort under J. Reilly Lewis, the Barocchisti under Diego Fasolis, the Al Ayre Espanol under E.López-Banzo, the Camerata Stuttgart, the Orchestra of Patras,  the Athens and Thessaloniki State orchestras, the Camerata-Friends of Music Orchestra, the Greek Radio Orchestra, the Orchestra of Colors, and the orchestras of the City of Athens and the City of Thessaloniki.

Her recordings of Handel’s operas Oreste (as Oreste), Arianna in Creta (as Teseo) and Tamerlano (as Andronico) under George Petrou (by MDG, Germany) were received with the highest praise from the international press. She performs Antiope in the DVD of Ercole su'l Termodonte, Polinesso in the DVD of Ariodante and Mitrena in the DVD of Motezuma, under Alan Curtis (Dynamic). She has also recorded D. Scarlatti's Tolomeo (as Dorisbe) (Deutsche Grammophon), Handel's Berenice (as Arsace) (Virgin), and recently a solo CD Salve Regina (Deutsche Harmonia Mundi), under Alan Curtis and also Handel's Giulio Cesare (as Sesto) (by MDG), under George Petrou.

Mary-Ellen Nesi has given many recitals and baroque music concerts and has premiered works by contemporary Greek composers at home and abroad.

Ιn 2003 she founded the Opera Festival of Ancient Corinth,  which stages operas inspired by ancient Greece in the archeological site of Ancient Corinth.