[4] Walker began his acting career in 2006 as a child actor when he appeared on the late-night talk show Talkshow with Spike Feresten.

In the 2008 docudrama film, Front of the Class, where he played the antagonist role of Young Brad's Bully.

In 2016, Walker appeared in the horror drama series Fear the Walking Dead as Seth Geary.

[17] In 2018, Walker played the guest role as Sam Stoller in the action drama series Lethal Weapon.

[18] In 2020, Walker appeared on the first season of the DC Universe and The CW series Stargirl alongside Brec Bassinger, Yvette Monreal, Anjelika Washington, Cameron Gellman, Trae Romano and Meg DeLacy, in which he played the character of Henry King Jr./Brainwave.