She is best known for her roles as Josslyn Carver in ABC drama series Mistresses and Ava Sharpe in The CW superhero comedy-drama Legends of Tomorrow.

Macallan trained in dance in her youth and participated in classes with choreographers including Mia Michaels.

[citation needed] She earned a bachelor's degree in business administration from the University of Florida, and studied abroad for a term at Bocconi University in Milan, Italy.

After graduation, she studied acting in Los Angeles and New York.

In 2016, Macallan wrote, produced, and directed the short film Self, E. She submitted the film as part of her application to the Warner Bros. television directors workshop.