Lia Cirio began her training at Swarthmore Ballet Theatre with Lori Ardis. She went on to train at Central Pennsylvania Youth Ballet under the direction of Marcia Dale Weary and Darla Hoover, where she also studied privately with Theresa Crawford and Rafael Grigorian.

From 2008-2009, Cirio toured with Trey McIntyre Project, performing throughout the United States and the world. She danced principal roles in McIntyre's Reassuring Effects of Form, Poetry, and A Day in the Life, and originated roles in various new works by McIntyre.  

Her repertory with Boston Ballet includes featured and/or principal roles in classics such as Sir Frederick Ashton's Cinderella (Cinderella, Winter Fairy); George Balanchine's Prodigal Son, Chaconne, Coppélia, Jewels (Diamonds and Emeralds), Symphony in C (second movement), Symphony in Three Movements, Theme and Variations, Divertimento No.15, Episodes, Who Cares?, Concerto Barocco, The Four Temperaments, Ballo de la Regina, La Valse, Serenade, A Midsummer Night's Dream, Agon, Piano Concerto No. 2, and Kammermusik No. 2; Val Caniparoli's Lady of the Camellias (Olympe); Florence Clerc's La Bayadère (Nikiya, Gamzatti, Lead Shade) and Les Sylphides (the Sylph); Sorella Englund's La Sylphide (principal); Larissa Ponomarenko's Giselle (Giselle); Maina Gielgud's Giselle (Myrtha, Peasant pas de deux); Harald Lander's Etudes (the Ballerina); Vaslav Nijinsky's Afternoon of the Faun (principal nymph); Mikko Nissinen's Swan Lake (Odette/Odile, pas de trois, pas de cinq, Four Little Swans) and The Nutcracker (Sugar Plum Fairy, Dew Drop Fairy, Snow Queen, Arabian); Rudolf Nureyev's Don Quixote (Kitri, Mercedes, Queen of the Dryads); Marius Petipa's Sleeping Beauty (Aurora, Lilac Fairy, Woodland Glade Fairy) and Paquita (principal role), along with numerous pas de deux. She has danced principal roles in Peter Martins' Barber Violin Concerto; John Neumeier’s Third Symphony of Gustav Mahler; and Jerome Robbins' Antique Epigraphs and Glass Pieces.

Her contemporary repertoire includes works by William Forsythe, Jiří Kylián, Wayne McGregor, Jorma Elo, Christopher Wheeldon, Jeffrey Cirio, Alexander Ekman, Helen Pickett, Twyla Tharp, Mark Morris, among others. She originated roles in Elo's Carmen (Micaela), Brake the Eyes, Sharper Side of Dark, and Awake Only, along with numerous others.

At age 16, Cirio was awarded a Level One award from the National Foundation for Advancement of the Arts and was a Presidential Scholar in the Arts finalist. She was also awarded the top scholarship and Founder's Award by Barbara Weisberger at the Regional Dance America Festival. She was Boston Ballet’s Princess Grace Nominee in 2004. Cirio was named in Dance Magazine's first "On the Rise" feature article, and has been featured in additional articles in Dance Magazine, Dance Spirit, and on the cover of Pointe. She has been hailed as "one of the most accomplished actress-dancers in the company" by The Patriot Ledger, and as "an outstanding performer with tremendous stage presence" during Boston Ballet's Spain tour. She has performed in galas around the world including in the Philippines with Ballet Manila and in Mongolia and Japan with United Ballet Company. She has performed at the Lincoln Center and at the Guggenheim in Sonya Tayeh's Unveiling, as well as at Jacob's Pillow in Ballet Coast to Coast.

Cirio was the co-founder of Cirio Collective, where she serves as the Assistant to the Artistic Director, as well as a dancer. In 2018, Cirio made her choreographic debut with Sta(i)r(e)s during BB@home: ChoreograpHER. In 2019, she choreographed Lenore for the second ChoreograpHER installment, as well as …the peppermint wind for Boston Ballet School’s Next Generation. She choreographed Chesire for Ballet Academy East in New York City and will be choreographing world premieres for Festival Ballet Rhode Island and Boston Ballet's mainstage ChoreograpHER program in 2022.

At 16, Cirio was invited by Mikko Nissinen to join Boston Ballet II. She was promoted to Boston Ballet's corps de ballet in 2004, to second soloist in 2006, and to soloist in 2007. From 2008-2009, Cirio toured with Trey McIntyre Project, performing throughout the United States and the world. Following her time with Trey McIntyre Project, she returned to Boston Ballet for the 2009-2010 season and was named principal dancer in 2010.

Position funded by Laura J. Sen