John Karna is an American actor whose career began in the 2010s. He debuted in the 2012 comedy film Bindlestiffs. His next role was in another comedy feature Premature. Meanwhile, his first television appearance was on The Neighbors. At the same time, he had a notable guest role in an episode of Law & Order: Special Victims Unit playing Holden March. From 2015 to 2016, he became known for starring as Noah Foster on the MTV series Scream. Following this, he guest-starred on Chicago Fire and appeared in the film Sugar Mountain. He next played Greg Anrue in the acclaimed film Lady Bird. He’ll star on the upcoming miniseries Valley of the Boom.