Annable was born in Los Angeles, California. Her mother, Lydia (née Nodarse), is Cuban. Her father, Victor Yustman, who is of Italian and French descent, was born in Bogotá, Colombia, and raised in Nicaragua. After her graduation from Woodcrest Christian High School in Riverside, California, she had planned to earn a degree in business finance at Loyola Marymount University, and only then resume her career in acting full time, but she dropped that idea as irrelevant to her true passion for acting.
Annable made her acting debut at an early age, playing a young, Spanish-speaking student named Rosa in Kindergarten Cop. In 2007, she starred in the Lifetime original movie Reckless Behavior: Caught on Tape and followed it quickly with a lead role in J. J. Abrams' Cloverfield. In addition to this, she made a short appearance in the John C. Reilly comedy film Walk Hard. She also provided the voice of the character Amata in Fallout 3. She is featured in the 2009 music video for "(If You're Wondering If I Want You To) I Want You To" by Weezer. In February 2013, Annable signed on for the lead role of the ABC drama pilot Westside produced by McG and developed by Ilene Chaiken, but it was not picked up as a series.