In the 1990s, Rankin performed in Shakespeare's plays Love's Labour's Lost, Romeo and Juliet and The Tempest.
Rankin has appeared in over 50 films and television shows, including guest star roles on Hemlock Grove, The Mentalist, House, Monk, Without a Trace, The District, Chicago Hope, Ally McBeal and The Drew Carey Show. She has also had lead roles in independent films and television movies such as Molly's Game, Seven in Heaven and One of Our Own.
While training with the Stratford Festival Young Company, she spent four years with the Stratford Shakespearean Festival playing classical roles, such as Miranda in The Tempest. She has also danced the ballet role of Louise in Carousel at the same festival. Other stage appearances include Cosette in Les Misérables and Juliet in Romeo and Juliet.
She is known for starring as Mary in Son of a Critch, and for her recurring roles including Kate Heightmeyer in Stargate Atlantis and Fleur de Brabant in the supernatural fantasy Forever Knight. She has also guest-starred in The Outer Limits, Sleepwalkers, Charmed and Star Trek: Voyager.
In 2019, Rankin originated the role of Cynthia Murphy in the first International Production of Dear Evan Hansen in Toronto. She continued in the role in the show's tour of North America.
