Alexandra Pullen was born in Nashville, Tennessee, and was raised in Chicago, Illinois, where she began her initial ballet training at a local community center. Pullen studied at Dance Center Evanston, Evanston School of Ballet, and Chicago Ballet Arts, and also at the Ruth Page School of Dance, where she joined their company, the Civic Ballet of Chicago. She trained on scholarship at the Joffrey Academy of Ballet in Chicago under Anna Reznik and Alexei Kremnev. She toured with the Joffrey Trainees to perform as Clara in The Nutcracker Suite. She studied on scholarship at summer programs of the San Francisco Ballet School, School of American Ballet, Pacific Northwest Ballet, and American Ballet Theatre. In 2012, Pullen competed in the Youth America Grand Prix Chicago Semi-Finals and received a gold medal in the classical category and a silver medal in the contemporary category. She was a Finalist in New York City. In September 2012, Pullen was awarded the Shoot for Change Scholarship to attend the Jacqueline Kennedy Onassis School at ABT, and joined ABT Studio Company two weeks later.
Pullen joined ABT as an apprentice in 2013.