Taylor-Klaus began acting in Shakespeare plays while in the third grade. However, their first professional acting role was that of Bullet, a homeless street-wise lesbian teen, on the third season of the AMC crime drama series The Killing, which aired in 2013. Writing about playing Bullet, Taylor-Klaus said: “to be an actor is to want to visit the dark places that humans strive so hard to stay away from.”

From 2013 to 2015, Taylor-Klaus played the recurring role of Sin in The CW superhero drama series Arrow.

After gaining prominence from roles in The Killing and Arrow, they went on to play several guest roles in numerous television series, including Glee and iZombie. In 2016, they began voicing the starring role of Katie “Pidge” Holt in the Netflix animated series Voltron: Legendary Defender.

In November 2016, Taylor-Klaus came out as gay on Twitter, saying: “hello my name is bex and yes the rumors are true I am gay.” In July 2018, Taylor-Klaus came out as non-binary and stated a preference for they/them pronouns.

Taylor-Klaus had a starring role as Taylor in the slasher horror film Hell Fest (2018). They also starred as Hannah Perez in the 2018 musical comedy film Dumplin’, which is a film adaptation of Julie Murphy’s New York Times bestselling young adult novel. The film, which co-stars Jennifer Aniston, was directed by Anne Fletcher. Taylor-Klaus also played Violette Paich in Mario Sorrenti’s horror film Discarnate (2018).

In August 2019, Taylor-Klaus got engaged to their girlfriend, actress Alicia Sixtos and married in October 2020.