In 2007, she began a recurring role in the NBC drama series Friday Night Lights (2007-08) as Carlotta Alonso. In 2010, Alonso starred in the short-lived ABC drama series My Generation. From 2012 to 2013, she starred in the NBC post-apocalyptic series Revolution as Nora Clayton. Alonso later starred in the first season of another NBC series The Night Shift as Dr. Landry de la Cruz, that aired on the summer of 2014. In 2015, she had a recurring role in the BET drama series Being Mary Jane.

Alonso was born in New York City. Her mother is Puerto Rican, and her father is Peruvian, of native and Japanese descent. She has a brother. She has participated in karate, in which she holds a fourth level green belt. She loves animals and supports PETA, posing in a 2013 advertising campaign that asked consumers to wear synthetic leather.

In 2015, Alonso starred in two films; first was Re-Kill a horror film, and the box office hit comedy Paul Blart: Mall Cop 2 opposite Kevin James. In 2016, she starred in the first season of TNT crime drama Animal Kingdom. The following year, she went to star in the ABC drama pilot Las Reinas, but it not was picked up to series. She later had a recurring roles on Criminal Minds and The Resident. In 2019, she joined the cast of The CW prime time soap opera Dynasty replacing Ana Brenda Contreras in the role of Cristal Jennings.