Isabella Boylston was born in Sun Valley, Idaho, where she began dancing at the age of three. She grew up in Colorado and Sweden. While training at the Academy of Colorado Ballet, she won the gold medal in 2001 at the Youth America Grand Prix Finals in New York City. Starting in 2002, she trained at the Harid Conservatory in Boca Raton, Florida on a full tuition scholarship.
She joined the ABT Studio Company (now ABT II) in 2005, the main Company as an apprentice in May 2006 and the corps de ballet in March 2007.
Boylston's repertory with the Company includes an Odalisque in Le Corsaire, a fower girl in Don Quixote, the peasant pas de deux and Moyna in Giselle, a Harlot in Romeo and Juliet, the Fairy of Fervor in The Sleeping Beauty, the second shades variation in La Bayadère, the pas de trois and the Polish Princess in Swan Lake, and roles in Ballo della Regina, Brief Fling, Désir, and From Here On Out, Alexei Ratmansky's On the Dneiper, and Fancy Free. She created leading roles in Citizen and Everything Doesn't Happen at Once.
She is also a member of Benjamin Millepied's touring company Danses Concertantes and has danced in Millepied's Without, William Forsythe's Steptext, the black swan pas de deux, and Calliope in Apollo. Boylston won the 2009 Princess Grace Award.