Celli was born on June 6, 1923 as Teresa Levis in
Dysart, Pennsylvania. One of ten children born to an Italian family, she relocated with her family to
Milan, Italy when she was just five years old because her father had inherited an estate there. Her grandmother, Maria Scagnet, and her great-grandmother, Mme. Duval Celli, both sang opera, and it was from the latter that Teresa Levis took her professional last name, "Celli." While she lived in Italy, Celli was a student of soprano Ersilde Cervi Caroli. Sometime during
World War II, she returned to the United States, but then returned to Italy when the war ended. She later became the first wife of actor
Barry Nelson, and was married to him from 1951 to 1965. ==Music and film career==