Born in Georgia, George Oniani graduated from the Tbilisi State Conservatoire and continued his studies in Munich and at the Accademia Teatro alla Scala in Milan. His first operatic engagements in his native Tbilisi were Duca (Rigoletto), Cavaradossi (Tosca), Don José (Carmen), Radames (Aida), Riccardo (Un Ballo in Maschera), Manrico (Il Trovatore), Samson (Samson et Dalila) and the title role in Verdi’s Don Carlo.
George Oniani appeared at Teatro alla Scala in Milan as Riccardo in Verdi's Oberto and repeated this role later at Teatro Carlo Felice in Genova. He sang Arrigo (I Vespri Siciliani) at the Verdi Festival in Busseto and the Ravenna Festival and performed Ugo in Donizetti’s Ugo, Conte di Parigi at Teatro alla Scala and Teatro Bellini in Catania. In the meanwhile George Oniani’s repertoire consists of 40 leading roles such as Turiddu, Riccardo, Manrico, Rodolfo, Cavaradossi, Radames, Canio, Pinkerton, Don José, Pollione, Calaf, Laca (Jenufa), Boris (Katya Kabanova), Carlo VII (Giovanna d’Arco) and Foresto (Attila).
Since 2008/2009 George Oniani is a member of the ensemble of the Bonn Opera and has appeared as a guest at the opera houses in Milan, Catania, Brescia, Cremona, Pavia, Como, Mantova, Amsterdam, Rotterdam, Poznan, Rio de Janeiro, Vienna Volksoper, Kiel, Tallinn, Vilnius, Riga, Zagreb and the Festivals in Dalhalla, Macau, Toscana, Heidenheim and Kazan.