He expressed a desire to play the DC Comics character Dick Grayson/Nightwing in a live-action film upon learning that he was a popular choice among fans for the role.
He initially turned down an offer to attend Juilliard to look for acting work in Los Angeles. He auditioned a year later and was accepted again.
His father Peter Wittrock is also an actor and his mother Kate is a professor of occupational therapy at the University of Southern California.
He grew up in Los Angeles, where he attended the Los Angeles County High School for the Arts.
His father is of Danish, Norwegian, and Austrian descent. The surname Wittrock originates in Denmark.
Is pigeon-toed, meaning his feet angle towards each other when standing or walking.
Nominated for the 2018 Emmy Award in the Outstanding Supporting Actor in a Limited Series or Movie category for his role as Jeffrey Trail in American Crime Story (2016), but lost to Jeff Daniels from Godless (2017).