Björling (surname also spelled as “Bjoerling” and “Bjorling” in English-language sources) was born in Borlänge, Dalarna, Sweden, in February 1911. The midwife’s register shows he was born on 5 February; however, the church baptism records erroneously show 2 February, and this was the day on which he celebrated his birthday throughout his life. He was initially taught to sing by his father, David, an accomplished vocalist, and made his debut public appearance at the age of four with the Björling Male Quartet. The group performed in concerts throughout Sweden and the United States for eleven and a half years. He later studied opera with John Forsell.
Björling made his professional operatic debut as the Lamplighter in Manon Lescaut at the Royal Swedish Opera in Stockholm in 1930. This was soon followed by Don Ottavio in Mozart’s Don Giovanni, Arnold in Rossini’s William Tell and Almaviva in Rossini’s The Barber of Seville. This in turn led to engagements in Europe and the United States. Björling made his American concert debut in Carnegie Hall in 1937; the following year, he made his debut at the Metropolitan Opera as Rodolfo in La bohème.
Björling went on to become one of the principal singers at the Metropolitan Opera during the 1940s and 1950s, with an interruption during World War II. He sang many major tenor roles in operas in the French and Italian repertoire, including Il trovatore, Rigoletto, Aida, Un ballo in maschera, Pagliacci, Cavalleria rusticana, Faust, Roméo et Juliette, La bohème, Madama Butterfly, Tosca, and Manon Lescaut.
In December 1940, Arturo Toscanini invited him to sing the tenor part in Beethoven’s Missa Solemnis in New York, a recording of which exists. He also performed the Verdi Requiem under Toscanini in 1939 in Lucerne, Switzerland, and in November 1940 in New York, another performance eventually transferred to recordings.
One of Björling’s first LP sets was a 1950 performance of the complete Il trovatore, with Zinka Milanov, for RCA Victor. In 1953, he recorded the role of Turridu in a complete version of Cavalleria rusticana opposite Milanov for RCA Victor, but because Victoria de los Ángeles was under contract to EMI, the recording of the complete Pagliacci, made concurrently with Cavalleria, was not released by RCA, but by EMI. Robert Merrill appeared on both albums, but Leonard Warren was featured only on the Pagliacci one, as Tonio.