New York City Ballet (NYCB) is a ballet company founded in 1948 by choreographer George Balanchine and Lincoln Kirstein. Léon Barzin was the company's first music director. Balanchine and Jerome Robbins are considered the founding choreographers of the company. City Ballet grew out of earlier troupes: the Producing Company of the School of American Ballet, 1934; the American Ballet, 1935, and Ballet Caravan, 1936, which merged into American Ballet Caravan, 1941; and directly from the Ballet Society, 1946. In a 1946 letter, Kirstein stated, "The only justification I have is to enable Balanchine to do exactly what he wants to do in the way he wants to do it." He served as the company's General Director from 1946 to 1989, developing and sustaining it by his organizational and fundraising abilities.

The company was named New York City Ballet in 1948 when it became resident at City Center of Music and Drama. Its success was marked by its move to the New York State Theater, now David H. Koch Theater, designed by Philip Johnson to Balanchine's specifications. City Ballet went on to become the first ballet company in the United States to have two permanent venue engagements: one at Lincoln Center's David H. Koch Theater on 63rd Street in Manhattan, and another at the Saratoga Performing Arts Center, in Saratoga Springs, New York. The School of American Ballet (S.A.B.), which Balanchine founded, is the training school of City Ballet. After the company's move to the State Theater, Balanchine's creativity as a choreographer flourished. He created works that were the basis of the company's repertory until his death in 1983. His vision influenced dance both across the United States and in Europe. He worked closely with choreographer Jerome Robbins, who resumed his connection with the company in 1969 after having produced works for Broadway.

NYCB still has the largest repertoire by far of any American ballet company, and it often stages 60 ballets or more in its winter and spring seasons at Lincoln Center each year, and 20 or more in its summer season in Saratoga Springs. City Ballet has performed The Nutcracker, Romeo and Juliet, A Midsummer Night's Dream, and many more. City Ballet has trained and developed many great dancers since its formation. Also, many dancers with already developed reputations have joined City Ballet as principal dancers.