Milner was born Huckleberry Milner in New York City, New York in 2008.

He discovered his passion for acting when he followed his sisters into community theatre at 4 years old. His professional debut was the role of Dash in Incredibles 2, replacing Spencer Fox.

Milner continues to act professionally in theatre and voice-overs. Besides acting, he enjoys hockey, skiing, and playing the bass. He loves Thor, Ironman, and Spiderman.

Milner has stated that he would like to one day eliminate homelessness in New York City.