Nico Castel (August 1, 1931 – May 31, 2015), born Naftali Chaim Castel Kalinhoff, was a comprimario tenor and well-known language and diction coach, as well as a prolific translator of libretti and writer of books on singing diction. Although Castel performed throughout Europe, North America and South America, he was best known for his nearly 800 performances at The Metropolitan Opera, where he also served as staff diction coach for three decades.
Castel was born in Lisbon, Portugal, the "scion of a multigenerational dynasty of Sephardic rabbis" with roots in 15th century Castile. He was raised in Venezuela by multilingual parents and a German nanny and attended a French school. After some vocal study in Caracas and then the University of Mainz in Germany, Castel moved to New York City at the age of 16 to pursue a singing career and to study romance languages at Temple University in Philadelphia. In the early 1950s, he served in the United States Army as a translator in Germany.
In 1958, he became the first winner of the "Joy in Singing" award, which launched his career with a recital at The Town Hall in New York City. He began calling himself "Nico Castel" early in his singing career. In June 1958 he made his debut with Santa Fe Opera as Fenton in Verdi's Falstaff. The following month he portrayed Joseph in the world premiere of Carlisle Floyd's Wuthering Heights in Santa Fe. In 1965, he first performed with the New York City Opera as Jacob Glock in The Flaming Angel and performing with that company in numerous roles thereafter. With the Metropolitan Opera in 1970, he debuted as Don Basilio in Mozart's The Marriage of Figaro. Over the next 27 years at the Met, he gave nearly 800 performances and later served for three decades, until his retirement in 2009, as its staff diction coach.