She undertook music studies in Seoul, where she graduated in singing and piano. She moved to Rome in 1983 where she was able to complete her singing studies by graduating from Santa Cecilia in 1985. She won the most important international competitions. Her debut at the Teatro Verdi in Trieste in 1986 with resounding success brought her to Salzburg by Maestro Karajan and opened the doors of the greatest theatres: The Metropolitan in New York, La Scala in Milan, Covent Garden in London, Staatsoper in Vienna, La Bastille in Paris, Madrid, Brussels, Tel Aviv, Los Angeles...In her amazing career, Sumi Jo has sung Lucia di Lammermoor, Rigoletto, les Contes d'Hoffmann, Un Ballo in Maschera, Elisabetta d'Inghilterra, I Puritani, l'Elisir d’amore, Ariadne auf Naxos, Fra Diavolo e Fetonte, without forgetting the role of Queen of the night that she has played a hundred times, in different parts of the world, from Europe to Asia and in all the Americas. She sang at the Opening of the Sydney Olympics, and at the Soccer World Championships in Japan, Korea and South Africa. Her discography is very wide and includes about fifty recordings: she started with "Un Ballo in maschera", the last recording made by H. von Karajan, then several works by Rossini including: Le Comte Ory (Gardiner), Il Turco in Italia (Marriner), the Mass Solemn, and Tancredi under the direction of Alberto Zedda who was nominated for the prestigious Grammy Award. She also recorded three editions of Mozart's Magic Flute (Solti/Jordan/Oesterman), as well as Mahler's Eighth Symphony with Sinopoli and Carmina Burana with Mehta and the world premiere of the first version of Ariadne auf Naxos by Strauss. She won the famous David di Donatello award, and she was nominated for an Oscar for the best song in Paolo Sorrentino's movie YOUTH where Sumi Jo played herself. Lately the President Sergio Mattarella has awarded her the honour of Knight of the Order of the Star of Italy.