Cassandra Trenary, a native of Georgia, began training at age three at Lawrenceville School of Ballet. She joined the school's company, Southern Ballet Theatre, in 2006 under the direction of Phyllis Allen. She performed various contemporary works with SBT in addition to full-length ballets. Trenary received additional training at Southeast Regional Ballet Association conventions and performed in various pieces, including the lead role in Defy.
In 2009, Trenary received a SERBA Star Student award. From 2006-2010, she was an American Ballet Theatre National Training Scholar and attended the Summer Intensive in New York City from 2007 through 2010. She was a 2011 National YoungArts Foundation Winner and through YoungArts became a 2011 U.S. Presidential Scholar in the Arts Nominee.
Trenary studied at the Jacqueline Kennedy Onassis School at American Ballet Theatre and performed with ABT II on their 2011 European tour. She joined American Ballet Theatre as an apprentice in April 2011 and became a member of the corps de ballet in November 2011.
Her repertory includes Columbine, the Chinese Dance and one of the Nutcracker's Sisters in Alexei Ratmansky's The Nutcracker, the Younger Sister in Pillar of Fire, the Diamond Fairy and the Fairy Canri qui chante (Canary) in The Sleeping Beauty, a little swan and the Polish Princess in Swan Lake, roles in Bach Partita, Drink to Me Only With Thine Eyes, Private Light, Raymonda Divertissements and Sinfonietta, and The Final Frame, created by Zhong-Jing Fang. She created Princess Florine in Alexei Ratmansky's The Sleeping Beauty.