Sierra Armstrong was born in Grapevine, Texas and began dancing at the age of five at a local dance studio in Winston Salem, North Carolina. In 2006, she was invited to attend the University of North Carolina School of the Arts (UNCSA) Preparatory Program where she trained under the direction of Dayna Fox until 2013. Armstrong continued her ballet training in the UNCSA High School Program under the direction of American Ballet Theatre alumna Susan Jaffe. Armstrong attended summer intensive programs at American Ballet Theatre (New York), School of American Ballet, Houston Ballet, Pacific Northwest Ballet, Joffrey Ballet (New York) and Cary Ballet Conservatory, all on merit scholarships. Asa student, her repertoire has included Sugar Plum Fairy and Clara in Ethan Stiefel’s The Nutcracker, George Balanchine’s Allegro Brillante, Stanton Welch’s Long and Winding Road, Oliver Halkowich’s Procession to the Club and Divya Rea’s Harmonic Dissonance.
At the age of 15, Armstrong was a finalist at the Prix De Lausanne competition in Switzerland and received a full scholarship to the American Ballet Theatre Jacqueline Kennedy Onassis School. She placed second in the classical division and Top 12 in the contemporary division at the 2015 Youth America Grand Prix Semi-Finals in Indianapolis, Indiana.
Armstrong joined ABT Studio Company in January 2016, where her repertory included Alexei Ratmansky’s Bolero, George Williamson’s Murmuration, La Bayadère Pas d’Action, Frederick Ashton’s Birthday Offering and Raymonda in Raymonda Pas de Sept. As a Guest Artist she danced the role of Sugar Plum Fairy in Washington Rock Ballet and Warwick High School’s The Nutcracker.
Armstrong joined American Ballet Theatre as an apprentice in 2017.