Lillian DiPiazza received her early training at Maryland Youth Ballet and at School of American Ballet (New York City Ballet). She attended Ballet Dortmund in the summer of 2011 and International Ballet master classes in Prague in 2011. She was a 2010 Special Talent in the Aronofsky film Black Swan, a 2007 NFAA youngARTS winner in dance and winner of the bronze medal at the 2006 USA National Youth Ballet Competition.
Beginning in 2008, Lily joined Pennsylvania Ballet II under director William DeGregory. Her lecture-demonstration performances there included Balanchine's Tchaikovsky pas de deux variation, The Four Temperaments and Dying Swan.
In 2009, Lily was promoted from PBII to the Pennsylvania Ballet proper. Until her recruitment by Ballet Next in June 2012, Lily appeared frequently in PB performances, including woman 1 in Forsythe's The Vertiginous Thrill of Exactitude, pas de trois and Spanish divert. in Christopher Wheldon's Swan Lake, 1st corps girl in Roland Petit's Carmen, lillies and Tybalt's lady in John Cranko's Romeo and Juliet, the Mistake Waltz in The Concert by Jerome Robbins, corps in Agnes DeMille's Rodeo and in Stevenson's Cinderella, quartet corps in Twyla Tharp's Push Comes to Shove, Benjamin Millepied's This Part in Darkness, featured ensemble in Carmina Burana by Matthew Neenan, learned solo girl in Wheeldon's Polyphonia and corps in Ashton's La Fille mal Gardée. Of Balanchine's works, while with Pennsylvania Ballet Lily performed 2nd solo in Raymonda Variations, 10 girls in Who Cares?, demi-corps in Square Dance, sanguinic corps in The Four Temperaments, snow and demi-flower and marzipan corps in The Nutcracker and corps in Agon, Theme and Variations, Concerto Barocco and Ballo della Regina.