María José Siri was born in Uruguay. In 2006 she sang Musetta in La Bohème at Teatro Colon of Buenos Aires. At Teatro Argentino de La Plata and Teatro Municipal de Santiago de Chile she sang Leonora in Il Trovatore, Violetta in La Traviata in Teatro Solis and in Teatro Argentinoas Countess of Le Nozze di Figaro. In 2007 she sang Violetta in La Traviata and Verdi’s Requiem at Teatro Colon. She also debuted at the Rheingau Festival in Wiesbaden. and she made her Italian debut with Le Villi of Puccini in Mantova, Novara and Rovigo.

In 2008 she sang Leonora in Il Trovatore in Genova Mimì at Semper Oper Dresden, and in Verdi's Requiem with the Berliner Philharmonic in Berlin, La Traviata at the Sankt Margarethen Festival and Aida in Stuttgart and in Palermo, (Franco Zeffirelli). In 2009 she sang I Due Foscari and the title role in Aida with Daniel Barenboim at La Scala di Milano. She also sang the Aida La Scala-production in Tel Aviv, Nedda in Pagliacci at Maggio Musicale Fiorentino (director Franco Zeffirelli) and Mitridate re di Ponto at the Mozart Festival in La Coruna (director Graham Vick). 2010 began with La Juive at Mihailovsky, St. Petersburg. Her future includes Aida in, Stuttgart, Bregenzer Festspiele and Florence (with Mehta), Tosca in Genova and Savonlinna, I Due Foscari in Trieste, Il Trovatore in Palermo and Manon Lescaut in Santiago.