After three years with the Monte Carlo Opera, Farrar made her debut at the New York Metropolitan Opera in "Romeo et Juliette" on November 26, 1906. She appeared in the first Met performance of Giacomo Puccini's "Madama Butterfly" in 1907 and remained a member of the company until her retirement in 1922, singing 29 roles there in 672 performances. She developed a great popular following, especially among New York's young female opera-goers, who were known as "Gerry-flappers". Farrar created the title roles in Pietro Mascagni's "Amica" (Monte Carlo, 1905), Puccini's "Suor Angelica" (New York City, 1918), Umberto Giordano's "Madame Sans-Gêne" (New York, 1915), as well as the Goosegirl in Engelbert Humperdinck's "Königskinder" (New York, 1910), for which Farrar trained her own flock of geese. According to a review in the "New York Tribune" of the first performance, "at the close of the opera Miss Farrar caused 'much amusement' by appearing before the curtain with a live goose under her arm."